Will the any of the vaccines under development for COVID-19 work to protect the population given a timeline of the next 12 months? This is a crucial question.
I have thought quite a bit about handicapping the chances of success for many of the COVID-19 vaccines in development (but probably not all 250!). The stakes for these vaccine projects are high and the investment is remarkable. Today, Pfizer was given a $2 billion contract to provide COVID-19 vaccines to the US while a couple of weeks ago Novavax got $1.6 billion for a similar promise. This is an extraordinary amount of money even for the federal government!
Given the many different technologies being used for these vaccines, the incredibly compressed time frames for development and the variability in the human immunity to COVID-19, I thought it would be useful to first outline the overall reasons why any of these vaccines might be successful. Over the next few weeks, as more of the initial clinical trials of these vaccines are reported, I will provide a more technical review of the specific vaccines and the different assets. But for now, I will address the general issues on the success and failure of these vaccines.
Reasons why a COVID-19 vaccine will work.
1) Many different technologies are being tried. We aren’t putting all of our hopes behind one approach.
2) The key parts of the SARS-CoV-2 virus (proteins) that are important to prevent infection are known. Several vaccines actually include more than one of these proteins.
3) The trials are being conducted quickly, but are relatively large and well controlled.
4) Several vaccine candidates show the ability to induce immunity to the virus in humans.
5) The vaccines seem to induce several forms of immunity necessary to protect against viral infection.
6) The immune response to some of the vaccine candidates is in some ways similar to the immunity seen in patients recovering from COVID-19.
7) Many of the most experienced pharmaceutical and biotechnology companies are involved in the development of these vaccines.
Reasons why none of the vaccines will be successful.
1) Most of the technologies have never been successful as vaccines in humans. Several have failed as human vaccines for other diseases.
2) Many traditional vaccine technologies (killed whole virus) are not being pursued (except in China).
3) The testing is being done in young healthy people, not in the elderly and ill who need the vaccine most.
4) The endpoints in the trials do not show protection from COVID-19. There is no trial that actually challenges people with the SARS-CoV-2 virus and shows that a vaccine is protective.
5) The exact type and degree of immunity to prevent COVID-19 infection is not known.
6) Most of the vaccines in early trials have shown significant and disappointing side effects that could prevent a second dose necessary for protection. Fevers, muscle aches, head aches and nausea are prominent.
7) The long-term effects of the vaccines cannot be evaluated in these trials. This could make the side effect profiles worse.
8) No vaccine has been successfully developed for other coronavirus infections like SARS.
9) “Operation Warp Speed” has not clarified the specific criteria for success. The FDA has suggested a 50% reduction in infections, but the way this will be calculated is not clear.
10) People won’t take the vaccine even if it is approved. According to polling many are already distrustful of the process of how the vaccines have been chosen and are unlikely to take the vaccine even when it is approved.
At this point we must hope for success.