Post-vaccination: to mask or not to mask

Very short answer — to mask.

Slightly longer version (build upon episode #811 of the SGU, thank you very much Cara!).

Reason #1 (selfish one)

Let’s begin with two terms that are often used interchangeably though there is important difference between them:

• efficacy, which is looked at in pristine, lab conditions
• effectiveness, which is looked at in real-world conditions, taking into consideration variety of aberrations and shortcomings, like people who were late for the second dose, vaccine was thawed a bit too early, etc.

We know that the vaccines (Moderna and Pfizer) have about 95% efficacy, which means that 1 in 20 people could get infected even after being properly vaccinated and have safely been through first 6 weeks to let the body develop full immunity. And this is efficacy, not it’s real life cousin effectiveness.

When hopefully the majority of people will get vaccinated, then virus will not have enough of susceptible individuals to infect and consequently will not spread. However, for now folks who had had the vaccine are few and far between, thus even they are at non-negligible risk of getting sick.

Reason # 2 (compassionate one)

Can one spread Covid after being vaccinated? We do not know yet.

When manufacturers had developed the vaccines, apart from efficacy they looked at 1) does it keep people from getting sick and 2) is it safe. However, they did not look on whether or not it prevents the spread.

So how can one spread Covid after being vaccinated with a vaccine that does not contain viral particles ? Turns out, it depends on nature of virus and the vaccine. On one hand there is measles vaccine that works extremely well, because after it the person cannot get infected, hens cannot be a carrier, hens cannot spread it around. On the other hand there are the majority of other vaccines, including one against flu: they act by preventing a person from being sick via impeding developing high quantities of viral particles in their system. With the second group one can still have low quantities and therefore can spread the infection. For now, we do not now how Covid vaccine would behave regarding low load spread.

Now, there are some vaccines that are delivered orally or nasally (flu, polio) as opposed to an injection, and it seems that the former are superior to the latter, as they induce strong local immunity on the spot, where the vulnerable target cells for those viruses are located. Currently, all of the approved Covid vaccines are injectable and those cause a systemic immune response, which might allow for low level infection in the upper respiratory part of respiratory system and thus enabling spread, which is especially important while most of the people have not been vaccinated.

Reason #3 (compassionate again)

And here we come to the eternal argument in favor of vaccinating in general — not everyone will be able to get a vaccine due to a health condition or a medication they depend upon to live, other will not be able to develop a sufficient immune response to protect themselves. A few people who took part in vaccine trials had developed cancer and in this small subgroup the efficacy of the vaccine had been found around 76% only, and that again was in pristine lab conditions. So until we develop a herd immunity via vaccination, we have to continue wearing masks to protect those who cannot protect themselves.

Reason # 4 (selfish to finish with)

So far the shock about the spread of Covid variants has been dampened slightly, as specialists are hopeful regarding vaccines’ efficacy against them. But then again, we do not have enough data yet, and it is possible that in the future we’ll have to adjust the Covid vaccine periodically for new mutations as we do with flu vaccines. However, wearing a mask works variant or not.

TL;DR: wear a mask, covering both nose and mouth , keep washing hands, avoid crowds and gatherings, and keep your distance. We have been through a lot by now and it is the worst time to slacken our efforts. Everyone is tired and fed up, but if we want to have good old life back, we have to go on.