Healthcare workers

Some Healthcare Workers Have Pre-existing Immunity to Covid, Study Finds

The question of whether some people have pre-existing immunity to Covid has been with us since the early days of the pandemic. Many scientists initially assumed there would be little or no pre-existing immunity. After all, SARS-CoV-2 was novel, highly infectious virus that appeared well adapted for human transmission.

However, in the spring of 2020, scientists began to report cross-reactive T-cell activity in people who hadn’t been infected with the virus, and – in some cases – in those who hadn’t even been exposed. However, it remained unclear whether such T-cell activity played any role in immunity.

Were individuals with cross-reactive T-cells less likely to become infected? Were they less likely to get seriously ill, conditional upon being infected? We simply didn’t know. Some even speculated that T-cell activity might predispose to more severe disease…

Evidence is now emerging that T-cell activity does play a role in immunity. In a recent study, Chinese scientists studied Covid patients and their close contacts who did not become infected. They observed “significant levels of SARS-CoV-2-specific memory T-cell immunity” in the uninfected contacts, hinting at a role for T-cells in staving off infection.

In a separate study, the same group of scientists studied Covid patients who experienced varying degrees of disease severity. They found that activation of two types of T-cell was “strongly and inversely correlated” with the severity of disease. One caveat is that their sample comprised only 12 people.

The most convincing evidence to date comes from a recent study published in the Nature by a team of British scientists. Leo Swadling and colleagues followed 700 healthcare workers in London for 16 weeks during and after the first wave of the pandemic.

They identified a subset of participants who had never tested positive for Covid and were seronegative at week 16. They then matched these individuals by age, sex and ethnicity to participants who had been infected by week 16. They also matched them to healthy adults who’d been sampled before Covid began circulating.

What did the researchers find? The seronegative participants had SARS-CoV-2-specific T-cells that were “comparable in breadth” to those of participants who had been infected. What’s more, participants’ T-cells were higher in “magnitude and breadth” than those of the healthy adults sampled before the pandemic.

These findings strongly suggest (but do not prove) that some healthcare workers were protected against infection by pre-existing T-cell immunity.

One of the study’s authors, Francious Balloux, noted that the “ability to control infections through pre-existing T-cell immunity likely stemmed from constant pre-pandemic low-level exposure of HCWs to endemic coronaviruses”. If he’s right, than pre-existing T-cell immunity might be much less common in the general public.

Professor Balloux also cautioned that “X-reactive T-cell immunity may not be sufficient to control infections by the more aggressive α/δ strains”. (Recall that the study was based on data from the first wave, before Alpha, Delta or indeed Omicron had emerged.)

While more research is clearly needed, evidence suggests that pre-existing immunity to Covid has been underestimated. This is consistent with what scientists like Sunetra Gupta (co-author of the Great Barrington Declaration) have been arguing since last year.

Firing Nurses Who’ve Worked Through the Pandemic Is a Disgrace

Across the United States, nurses and other healthcare workers are being fired for not getting vaccinated. Is there any better illustration of the folly of our public health establishment?

These nurses have served on the frontline for more than eighteen months, helping to treat Covid patients day after day, while most of the people demanding vaccine mandates were sitting at home on their laptops.

“Thanks for all your hard work. Oh, you don’t want to get the vaccine? Well in that case, sayonara.” In addition to being mean-spirited, the policy of firing unvaccinated healthcare workers doesn’t really make any practical sense. And that’s putting it charitably.

A large percentage of frontline healthcare workers have already been infected. This means the protection they have against reinfection is actually better than what the vaccines provide.

I reviewed some of the evidence in a recent post. But don’t take my word for it. New undercover footage shows Pfizer scientists saying that natural immunity is “probably” better than immunity from the vaccines.

As I mentioned before, this doesn’t mean that nobody stands to benefit from vaccination. But it does undermine the case for making those who’ve already been infected get the jab. Their natural immunity works just fine.

This point has been made eloquently by the Great Barrington author Martin Kulldorff. In a recent article, he argued that hospitals “should hire, not fire, nurses with natural immunity”. Yet within a matter of hours, Kulldorff’s article had been censored by LinkedIn. (Such petty interference in the scientific debate is now routine on social media.)

So there’s absolutely no case for firing healthcare workers who have natural immunity. What about those who haven’t been previously infected?

Even here, the case for mandates is weak at best. We know that vaccine-induced immunity against infection wanes over time. Six months after vaccination, you’re not that much less likely to become infected than someone who’s never been vaccinated.  

This means that mandating vaccines for healthcare workers is no guarantee of safety. If there’s a ward full of vulnerable patients, ensuring that every nurse is vaccinated won’t necessarily prevent someone from catching Covid, and then spreading it to the rest.

The only surefire way of protecting vulnerable patients is testing everyone before they go into the ward. Positive test? Well, you’ll have to stay at home or work in another part of the hospital for the next few weeks.

There are also the rights of workers themselves to consider. If the vaccines had no side effects and offered lasting protection against infection, the case for mandates would be strong. But the vaccines do have side effects (albeit rare ones) and they don’t provide lasting protection against infection.   

As Oxford philosopher Julian Savulescu argues, autonomy is a core principle of medical ethics, so any policy that violates autonomy (such as mandatory vaccination) can only be justified if it confers substantial third-party benefits. Yet it’s not clear that Covid vaccines do confer such benefits.

What’s more, getting vaccinated isn’t the only way to reduce one’s risk of infection. Avoiding large gatherings is another. Should hospitals be able to require that their staff avoid large gatherings, so as to reduce the risk of infection even further? Most of us would say “no” because it violates individual autonomy.

Of course, keeping Covid out of high-risk hospital wards is an important goal. And although mandatory vaccination is no guarantee of safety, it probably does have some effect, at least for the first few months.

Surely there’s a workaround for nurses who opt against vaccination? For example, they could be tested three times a week until they acquire natural immunity. The costs of such testing could even be deducted from their pay checks (although given the number of unused tests lying around, I don’t see the need).  

Firing healthcare workers who haven’t been infected is mean-spirited and unnecessary. Firing those who have been infected makes no sense at all. Never mind vaccine mandates; we need mandatory training for bureaucrats to make them understand natural immunity.