Covid-19 Vaccines

Updated 14-Jun-2021

This is meant to try and keep up with the latest science on the Covid-19 vaccines, some of which are appearing to be quite effective, and others not as much.

Vaccination Procedure

Most Covid-19 vaccines are a two-shot vaccination with 1-3 weeks between vaccinations, depending on the vaccine. However, a study indicated that waiting 12 weeks after the first inoculation created more peak antibodies with the Pfizer vaccine. The Johnson & Johnson is a single-dose vaccination.

That said, it is possible that there will be yearly booster shots (actually, not booster but tweaked formulas like with the yearly flu vaccinations) needed, as over time the immune response becomes weaker. This will likely become another yearly flu shot, only much more important and likely mandatory for broad swaths of the population.

Vaccine Technologies

Besides brands, vaccines can be grouped into the various approaches and technologies used to make them.

Effectiveness and Safety

While the mRNA vaccines are showing the most effective rates, the technology is newer than in most other vaccines. This means that there is less known about potential long-term side effects. That said, the risks of not vaccinating is much higher than the risks of vaccinating, with a few possible exceptions.

For high-risk individuals, any vaccination is better than no vaccination. Yes, there is a risk but it is much lower than the risk of a debilitating disease and death if one contracts Covid-19. A benefit of most vaccines is the attenuation of the Covid-19 infection and the much lower risk of serious disease and death. That said, more effective vaccines are much more relevant to those with higher risks.

Also, there have been pauses or discontinuances of both AstraZeneca and Johnson & Johnson over blood clot issues, though the scientific evidence is not complete.

For both high and low-risk individuals, the choices are the same: if one does not have a choice, choose to be vaccinated. If one has a choice, choose the safer and better vaccines.

Assessing Risk

Risk of taking a given vaccine needs to be weighed against not taking a vaccine, or taking a different vaccine. At the minimum:

  • Risk of not taking a vaccine = (risk of contracting Covid-19 * risk of serious illness or death from Covid-19)
  • Risk of taking a vaccine = (reduced risk of contracting Covid-19 * reduced risk of serious illness or death from Covid-19) + risk of serious illness or death from the vaccine itself
  • Risk of taking a different vaccine = (increased or reduced risk of contracting Covid-19 compared with other vaccine * increased or reduced risk of serious illness or death from Covid-19) + increased or reduced risk of serious illness or death from the vaccine itself

It appears fairly clear that even with the least safe and least effective vaccines that they provide more benefit from contracting and having a debilitating outcome from Covid-19, than additional risk from the vaccines themselves.

That said, there when given a choice, there are better and worse vaccines to take, as amply demonstrated by Government's willingness or lack of willingness to approve and/or import a given vaccine for their population.

Minimum Safety and Efficacy Approval

There are certain seals of approval which should be seen as the minimum in terms of safety and efficacy, and that is getting an emergency approval for use by the WHO.

Here is that list of WHO emergency use approval, which does not include Sinovac:

The WHO is currently assessing Sputnik V but has not yet approved it. The WHO has not approved Sinovac CoronaVac and Sinovac is not seeking approval at this time.

Then exclude those vaccines whose safety is in question:

  • AstraZeneca
  • Johnson & Johnson

(Both are recombinant adenovirus vaccines.)

Then exclude the less effective vaccine:

  • Sinopharm

And one is left with a list of two vaccines that are best-in-class:

  • Moderna
  • Pfizer

Best performing vaccines

The best performing vaccines are clearly the mRNA vaccines (Moderna, Pfizer), and the recombinant adenovirus vaccine Sputnik V. The nanoparticle vaccine Novavax is not yet available, though their data looks good so far. Hopefully their manufacturing will begin as they are slated to deliver a billion doses to COVAX which will help the poorest nations.

Given that Sputnik and Novavax are not yet approved by the WHO, at this point in time (May 2021) it is obvious there are two best choices: Moderna and Pfizer. Johnson & Johnson and AstraZeneca both have safety concerns (blood clots) and are less effective in any case. Sputnik appears to be effective but safety data is not yet available.

Vaccines for Children

Children 12-17 are now cleared for Pfizer, with Moderna coming soon (as of June 2021). It looks like Moderna and Pfizer will have vaccines approved for 4 years and older by end of 2021 / early 2022.

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