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.
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.
Besides brands, vaccines can be grouped into the various approaches and technologies used to make them.
- mRNA - a new technology, with highly effective rates. Moderna, Pfizer.
- Inactivated vaccine - uses dead virus. Sinovac CoronaVac, Sinopharm, CoviVac, Covaxin, others. These are the least effective vaccines, though they don't all perform the same.
- Recombinant adenovirus - older technology. Sputnik V, Sputnik Light, AstraZeneca, Johnson & Johnson. While Sputnik V appears to be effective, AstraZenica and Johnson & Johnson are less so.
- Protein Subunit (Nanoparticle) - Novavax, Medicago, Sanofi, not yet approved but good trial data
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.
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:
- Johnson & Johnson
(Both are recombinant adenovirus vaccines.)
Then exclude the less effective vaccine:
And one is left with a list of two vaccines that are best-in-class:
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.
Other Resources & News
- Why is the EU suing AstraZeneca?
- AstraZeneca Vaccine - was it really worth it?
- Brexit blinds Britain to AstraZeneca Blunders
- A year of scientific milestones - Nature
- NPIs, effectiveness, and coverage of vaccines is a simulated model which shows continuing NPIs (school closings, maskings) while vaccinating, and higher coverage with lower effectiveness vaccines is more effective than lower coverage with higher effective vaccines.
- Covid Update 10-06-21 NYTimes the Chinese are not confident in their virus and they will not reopen borders until mid 2022. They have only just begun mass vaccination (but are doing so quickly so far). You can't get to herd immunity with a vaccine that is 50% effective (or even 60% effective). According to the WHO, there is not enough data to approve Chinese vaccines for the over 60 year-olds (even though Thailand has already approved this).
- Efficacy Estimates for Various COVID-19 Vaccines: What we Know from the Literature and Reports