Symptoms

Stay Off Work If You Get Covid Symptoms – But Go to Work if You Get Covid Symptoms, Government Tells Public

Britons should go to work if they have a headache or feel tired – even though both are now officially recognised as Covid symptoms and the public is advised to stay at home if they have Covid symptoms – Health Secretary Sajid Javid said today. MailOnline has more.

Asked whether he would still go to work if he had a headache, Sajid Javid claimed he would “first reach for the Nurofen”. He said it would also depend “how tired I felt”. 

Health chiefs last week quietly expanded the list of tell-tale signs of the virus to warn of nine other symptoms. As well warning of headaches and feeling tired, officials also now say that a blocked or runny nose, a loss of appetite and feeling or being sick can signal that someone is infected.

The decision marked a huge change in the Government’s stance on symptoms, after acknowledging only three for the entirety of the pandemic (a fever, cough and loss or change to taste or smell), despite other countries and health bodies including up to 14.

The move coincided with the vast majority of employees in England no longer being able to get any free swabs as part of Boris Johnson’s “Living With Covid” strategy. Experts warned the axing of free tests for all but the most vulnerable – coupled with the expansion of the NHS symptom list – will trigger a “free for all” on staff absences, leaving workers to decide “whether or not they stay at home and for how long”. …

The NHS notes on its website that the now 12 Covid symptoms – which also include an aching body, a sore throat and diarrhoea – are “very similar to symptoms of other illnesses, such as colds and flu”. People experiencing these symptoms, who also have a temperature or don’t feel well enough to work, should “try to stay at home and avoid contact with other people”. They should also take “extra care” to avoid contact with anyone at higher risk from the virus.

Warnings of a Workplace Sickness “Free For All” as NHS Expands Covid Symptom List and Workers Advised to “Stay at Home” When Unwell

The Government’s scrapping of free Covid tests combined with an expansion to the NHS list of symptoms will trigger a “free for all” of staff absences, experts have warned. MailOnline has more.

The vast majority of employees in England are now unable to get any free swabs as part of Boris Johnson’s “Living With Covid” strategy.  

But health chiefs advise people to “stay at home” if they have any of the 12 newly-recognised symptoms, which can be “very similar” to ones brought on by colds or the flu.

It means, in the absence of a test, people suffering cold-like symptoms will be left to decide “whether or not they stay at home and for how long”, unions say.

Lucy Moreton, a professional officer at the ISU, the union for borders, immigration and customs, warned that it is “inevitable” staff will be off work with mild symptoms if they are unable to confirm whether or not they have Covid.

Unions also fear the chaos will only drive transmission up, with Covid levels already at a pandemic high in England and one in 12 people thought to be currently infected.

Only the elderly, most vulnerable and health and social care workers can access tests for free. Tests are, however, available at high street retailers such as Boots for £2. 

England’s mass swabbing regime – thought to cost up to £2billion-a-month – was ditched under Boris Johnson’s “Living With Covid” strategy.

It marked one of the final steps on the route back to normal life, after mandatory self-isolation rules were scrapped in mid-February.

Workers who test positive no longer have to legally self-isolate, although they are still advised to “stay at home and avoid contact with other people”. The NHS also says that they should take “extra care” to avoid making contact with anyone at higher risk of the virus. 

NHS Covid advice also says: “You can go back to your normal activities when you feel better or do not have a high temperature.'”

Worth reading in full.

Vaccines Have Failed to Prevent the Spread of Covid, Israeli Study Concludes

An Israeli study has looked at how much difference a fourth Covid vaccine dose makes compared with a third dose.

The study was restricted to triple-jabbed healthcare workers, and more specifically to those whose antibody levels were in the bottom 40% of the antibody levels in the cohort (a group comprising around 29% of the cohort). Of the 1,050 eligible healthcare workers, 154 were given a Pfizer fourth dose and 120 Moderna. The rest formed a triple-jabbed control group.

Measuring antibody levels, the researchers found an increase by around 10-fold following the fourth dose, restoring antibodies to the peak levels they hit following the third dose, though no higher.

The study was originally intended just to measure antibody levels and other indicators of immunogenicity. However, the Omicron surge in the country was so large that despite being a small study, enough infections occurred within the study groups to allow an estimate of vaccine effectiveness. The participants were PCR tested each week. The researchers reported that ‘breakthrough’ infections were common and, though mild, had high viral loads. During the study period, 25% of the control groups (triple-dosed) tested positive compared with 18-20% of the four-dose groups. This gave a fourth-dose versus three-dose vaccine effectiveness against PCR-positive infection of just 11-30% – though the small population size led to wide confidence intervals ranging from minus-43% to 55%.

Among the four-dose groups, there were 52 ‘breakthrough’ infections, of which 39 (75%) were classed as symptomatic. The vaccine effectiveness against symptomatic disease was estimated at 31-43%, though again with wide confidence intervals.

The symptoms of all PCR-positive infections were typically “negligible”, the researchers report, and in many cases the infections “would not have been tested or reported, without the active surveillance”. Yet they had relatively high viral loads (Ct around 25), so were presumably infectious. Thus, with a quarter of triple-vaccinated and a fifth of quadruple-vaccinated healthcare workers becoming infected and apparently infectious during the wave, the researchers conclude the vaccine programme is a failure as it is not preventing the spread of Covid: “The major objective for vaccinating [healthcare workers] was not achieved.” However, the apparent efficacy against severe disease and death means older and vulnerable people may benefit from a fourth vaccine dose, they say.

The study also looked at safety. It found that 80% of Pfizer recipients and 40% of Moderna recipients reported some kind of adverse reaction, though none were classed as serious. The adverse reactions are summarised in the chart below.

Larger studies on the efficacy and safety of the fourth dose, which has now been rolled out (having gone ahead without waiting for studies such as this one), are forthcoming, the researchers note.

Half of People Deliberately Infected With Coronavirus Did Not Get Sick, Study Finds

Researchers inoculated (exposed) 36 people aged 18-29 with SARS-CoV-2 (Wuhan strain) via nasal droplets in the first COVID-19 challenge trial. The dose was similar to that found in a droplet of nasal fluid (which seems on the high side compared to natural exposure – who inhales globules of snot?). What did they find?

First of all, two of the 36 were found to have developed antibodies between screening and inoculation, so although they were inoculated anyway they were excluded from most of the analysis (they didn’t develop an infection, unsurprisingly). That left 34. Of those, 18 (53%) tested PCR positive, 17 (50%) of them with symptoms and one without. This means 16 (47%) never tested positive, despite being heavily exposed via lying on their back for 10 minutes with a blob of infected snot up their nose. Why did they not get sick? The researchers say investigations of these questions are ongoing.

This raises an interesting question of what constitutes infection, as clearly all participants had been thoroughly exposed but for 16 of them their immune system dealt with it in some way without resulting in symptoms or PCR positivity. The proportion infected of 53% is higher than the proportion of the population typically infected in an outbreak, such as on the Diamond Princess (where 19% tested PCR positive), but that may be owing to the level of exposure or other transmission dynamics.

Interestingly, there was no correlation between symptom severity and viral load, measured both using Ct values from a PCR test and viable virus. Note the most symptomatic point in the charts below (the highest on the y-axis) does not have anywhere close to the highest viral load. Significantly, the one asymptomatic infection had no lower viral load or less viable virus than the symptomatic infections (the point sitting on the x-axis). This suggests that infectious asymptomatic infection may be a real phenomenon (though note this study did not test to see whether participants actually infected others).

qPCR is a Ct-based measure of viral load. FFA is a measure of viral load from viable virus.

Early Closure of Bars and Restaurants Had No Impact on the Spread of Covid in Japan

When comparing the impact of Covid in different countries, Japan is a clear outlier. In 2020, the country had zero days of mandatory business closures and zero days of mandatory stay-at-home orders. Despite seeing less change in mobility than major European countries, Japan has not had any excess mortality since the pandemic began.

As you may recall, the country hosted the Summer Olympics between 23rd July and 8th August. But even that did not lead to a large number of deaths. It has been suggested that Japanese people, and perhaps East Asians in general, have some degree of prior immunity to the virus.

In January of this year, Japan introduced restrictions on businesses for the first time. Specifically, 11 prefectures (including the capital, Tokyo) prohibited bars and restaurants from selling alcohol after 7pm, and forced them to close at 8pm.

In a recent preprint, Reo Takaku and colleagues investigated the impact of these measures on the spread of Covid. They began by checking whether the measures had their intended effect – of reducing the number of people frequenting bars and restaurants. This cannot be taken for granted: the night curfew in Greece had virtually no impact on mobility.

The researchers analysed survey data collected in the autumn of 2020 (when there were no restrictions in place) and the winter of 2021 (when there were restrictions in place). As the chart below indicates, the measures do appear to have had their intended effects.

The x-axis represents how far respondents lived from the border of a prefecture that introduced restrictions. The blue and green lines (corresponding to the right-hand y-axis) show the fraction of people who went to a bar or restaurant at least once in the relevant month.

The blue line corresponds to the autumn of 2020, and the green line corresponds to the winter of 2021. Notice that the green line is substantially flatter than the blue line, but only on the right-hand side of the chart. This suggests that restrictions did reduce the number of people frequenting bars and restaurants.

Long Covid Is Even Less Common Than Previously Thought

In a post on long Covid back in July, I said that “estimates of the chance of reporting symptoms after 12 weeks range from less than 1% to almost 12%”. That 12% figure came from the ONS, who found that individuals who tested positive were 12 percentage points more likely than controls to report at least one symptom 12 weeks after infection.

In my post, I argued that 12% is probably an overestimate on the grounds that some people who tested positive might have been inclined to exaggerated their symptoms – to report things they normally wouldn’t have done (thanks to all the media attention on long Covid).

And I noted that a study published in Nature Medicine had observed a much smaller percentage of people still reporting symptoms 12 weeks after infection, namely 2.3%.

A new analysis by the ONS has obtained a figure almost identical to that observed in the Nature Medicine study, namely 2.5% (the difference between the blue and green lines in the chart below). This is clearly much lower than its previous estimate.

Interestingly, the reason for the discrepancy with the earlier figure isn’t the one I suggested (i.e., that some people who tested positive were inclined to exaggerate their symptoms). Rather, it’s a statistical issue.

In both their original and updated analyses, the ONS defined symptom discontinuation as two consecutive visits without reporting any symptoms. (Participants in the ONS’s survey were visited at regular intervals for the purpose of data collection.)

This means that someone would be classified as ‘having symptoms’ if they’d gone one, but not two, visits without reporting any symptoms. However, in their original analysis, participants were only followed for a median of 80 days (less than 11 weeks).

As a result, some participants who would have been classified as ‘not having symptoms’ if they’d been followed a little bit longer were still classified as ‘having symptoms’ at the end of their observation period. (In the jargon, their follow-up time was ‘right-censored’.) This is shown in the diagram below, taken from the ONS:

In the ONS’s updated analysis, which followed participants for a median of 204 days, individuals in the situation of Participant D above were correctly classified as ‘not having symptoms’ before the end of their observation period.

Using this revised method, the ONS found that less than 1% of children aged 2-11 continue to report symptoms 12 weeks after infection, with the figure rising to just 1.2% for those aged 12-16. Hence long Covid is particularly rare in children, further undermining the case for vaccinating that age-group.

While the ONS deserves credit for being completely transparent about the limitations of their original analysis, their updated analysis is still open to the criticism I mentioned above. This means that 2.5% should probably be considered an upper bound on the chances of getting long Covid, the true figure being somewhat lower.

ZOE Data Shows Vaccines Cut Hospitalisation Risk by 64% once Infected, but Data on Frail Elderly is Less Positive

Professor Tim Spector, who leads the ZOE Covid Symptom Study, has done a new video update on vaccines, which is worth a watch. The team has also published a new study (not yet peer-reviewed) about the vaccines and their effect on symptomatic Covid.

The data is broadly encouraging in terms of efficacy. (They don’t address safety, though a previous study did. They also exclude the period immediately after each vaccine dose, so the study tells us nothing about any post-jab spike in infections, which is disappointing.)

One interesting finding is that sneezing becomes more common as a symptom of Covid infection after vaccination than beforehand, which the authors suggest could be a result of our immune system reaction changing. They note this could make the disease more infectious owing to the additional aerosols produced.

A concerning finding was that the elderly (over-60s) were up to three (2.78) times more likely to be infected after being vaccinated (with one dose of any vaccine) if they were frail than if they weren’t. This is unsurprising perhaps, but still indicative of considerably lower protection for those already at higher risk from the disease. Furthermore, a quarter of the vaccinated frail elderly in the study who contracted the virus ended up in hospital, which is not a small proportion (though no figure was given for the hospitalisation rate of unvaccinated frail elderly people against which to compare it).

Vaccine efficacy was also reduced in the obese, another high risk group, and those with an unhealthy diet – see charts below. The baselines are people who are also vaccinated and otherwise similar, but without the particular characteristic mentioned, e.g. the point in the top right shows the additional risk of infection that the vaccinated frail elderly have versus the vaccinated non-frail elderly.

Why Are People Unwell with Symptomatic COVID-19 Being Vaccinated?

Yesterday I wrote about the latest study from Public Health England that claims to show the vaccines are up to 90% effective in preventing symptomatic Covid infection in the over-65s, highlighting some shortcomings.

There was one aspect of the data that I didn’t comment on that is worth flagging up. The authors presented graphs showing how many people were being tested and testing positive according to how many days before or after their jab their symptoms began (all the tests in this study were on people with symptoms, the symptoms likely having prompted them to get a Covid test).

There are a few notable points about these graphs. The steep drop-off in tests ahead of the jab may be due to people deferring their vaccination when they get symptoms (Government guidance is that you should not have the jab if you are unwell), or it may be people with symptoms not getting tested because they don’t want to have to cancel their jab.

The big spike in tests in the day or two after the AstraZeneca jab (ChAdOx1-S) is probably people being tested after getting Covid-like side-effects from the vaccination.

Note the high positivity rate (yellow bars) in the days after each jab. This confirms the post-vaccination infection spike (though some of it may be Covid caught prior to the injection that subsequently becomes symptomatic).

However, the main point I want to draw attention to here is how many people with symptomatic Covid are getting vaccinated. The bars in the seven days prior to vaccination represent thousands of people with Covid-like symptoms who go on to get vaccinated, many while still symptomatic. The orange bars represent hundreds of people with PCR-confirmed symptomatic COVID-19, many of them with symptoms beginning in the two days immediately prior to the jab, who go on to get vaccinated anyway. This is despite Government guidance that people who are unwell, particularly with COVID-19, should be deferring their vaccinations. In addition to this, some of those thousands of people whose Covid symptoms begin on the day of the jab or in the days immediately following might have been pre-symptomatically infectious.

It has been suggested that the post-vaccination infection spike may be driven by the vaccination programmes spreading the virus. (Another plausible mechanism is that the vaccines cause temporary immune suppression; these mechanisms are not mutually exclusive and both could be operating.)

Here, then, we have direct evidence that hundreds of people with symptomatic, test-positive Covid (plus potentially thousands in the infectious pre-symptomatic phase) were turning up and being vaccinated anyway. This reinforces the idea that the vaccination programmes could be spreading the virus.

It also prompts the question: why were vaccinators not following Government guidance and refusing to vaccinate those who are unwell, particularly those with symptomatic COVID-19? Could they not foresee that that would spread the virus to those being vaccinated and those doing the vaccinating?