There are currently 27 vaccines in Phase 1 trials, 15 in Phase 2, and 9 in Phase 3. Both China and Russia have approved vaccines, but, um, there are some problems as none were ready for prime time yet. In fact, one of the Chinese vaccines was approved for single dose, and now they’re going to give everyone who got a first dose a second one, because one dose alone didn’t confer protection. You can see details on all of the vaccines here.
Source: New York Times, reprinted with permission.
The chart at the left presents information on the different trial phases. Sometimes Phases 1 and 2 are combined to speed up the process. And after Phase 3, there is an approval phase, although in some cases, there can be Emergency Use Limited Approvals.
These Phases are the same for the development of treatments, as well as vaccines, and sometimes for treatments, Emergency Use is a good idea. For example, let’s say that a drug for a Stage 4 cancer shows great promise. Because these patients are close to death, if a drug showed that it could buy patients an additional six months, when they only have weeks to live, Emergency/Compassionate Use may be warranted. There is limited concern about safety over efficacy if people are terminal.
With vaccines, you want to balance both safety and efficacy. You want to be sure that a vaccine offers protection and does not cause serious side effects. Can you do that in six months from molecule determination to the end of a Phase 3 study? Not hardly. Let’s be honest: we all want a vaccine. Or more accurately, all of us who see Covid-19 as a threat and not a hoax, can spell the word “science” correctly, and have ever read a newspaper, want a vaccine.
To understand what is being tested, and how those tests will be carried out, the drug companies write protocols. This is the one from Moderna. Pfizer has also published, and AstraZeneca says that they will be publishing soon. If you read it, you’ll see who they are testing their vaccine on, what they’re looking for, and what markers they will use to determine efficacy, safety and secondary considerations.
I receive a lot of questions about vaccines, so here goes….
Q: Will there be a vaccine prior to Election Day?
A: A real one? In the US? With data backing up safety and efficacy? NO.
Q: Will you, personally, take one of the vaccines?
A: Qualified yes. Before I take a vaccine, I will read all of the documentation on it that’s available. If it provides a minimum of 70% efficacy, and has shown no serious side effects for my cohort, then yes, I’ll probably take it.
Q: What does “70% efficacy” mean?
A: An efficacy rate relates to the proportionate reduction in disease among the vaccinated group. So, the measles vaccine (two doses) has an efficacy rate of 97%, meaning that almost everyone who gets the vaccine will avoid getting measles. The annual flu vaccine has an efficacy range of 50 – 70% meaning that at least half of the people who get it will either not get the disease, or, as is the case with the flu vaccine, get a much lessened set of signs and symptoms. The FDA is looking for an efficacy rate for the Covid vaccine in the 50% range, and the companies are shooting for 70%, although if you read the protocols, they are including mild illness in the 70%, which is troublesome.
Q: If you personally take the vaccine, will you give up your mask, social distancing and limitations?
A: ABSOLUTELY NOT. I’m one of those people who believe that Covid will become endemic rather than pandemic over time. Meaning that it will become something that never goes away, like the common cold, seasonal flu or noravirus. I believe that the treatments being developed will eventually mean that Covid becomes much less deadly, and can be treated earlier in the course of the disease, but that it will stay with us. Further, until there are enough people who have taken the vaccine, and we have effective testing and tracing in place, it’s still something to avoid, which means masks, social distancing and limitations.
As an aside, I keep up with the masks and related PPE that are being developed. Many are now on Indiegogo and Kickstarter, and some will work and some won’t. In addition, established PPE companies are also developing lines. The run the gamut from “that might well work” to completely insane. BUT I believe that over the next year, these devices will be available: they will be reusable, washable, have filters that can be replaced, and some will have dedicated air supply systems. While expensive, they will be game-changers. Currently “your mask protects me, and my mask protects you” but this new generation will provide 99.7% protection to the wearer.
Q: Do you have a favorite amoung the vaccine candidates?
A: Not yet. There’s not enough information on the efficacy and safety differences between the mRNA, whole inactivated virus and DNA candidates. In addition, some candidates utilize adjuvants, which are additives making vaccines more potent, and those are still in Phase 1. Those may well be far more effective.
Q: When do you think vaccines will really be available?
A: At this time, I’m looking at next summer at the earliest for the current Phase 3 candidates. In addition to the safety and efficacy considerations, there are concerns about distribution. The Phase 3 candidates require being kept at -70oC for both transport and distribution. While certain vaccines (e.g. chicken pox) require being frozen, that’s at a higher freezing temperature (up to -15oC) and can be held in a fridge for up to 72 hours before distribution. In addition, the pharma companies producing the chicken pox vaccine provide freezers to the pediatricians and others who administer the vaccine.
I don’t know where the money for these specialized freezers will come from. Think about it: you have a freezer in your house. How cold can it go? The Administration has said that the shots will be free to all – they will need to figure out how to pay for the freezers, the transport, storage, ancillary vaccine accoutrements (e.g. alcohol swabs, band-aids, etc.) It would be unreasonable to expect already strapped local health departments, hospitals, and other distribution points to be able to cover those costs. I don’t see the funding coming out of the current Congress and approved by the Administration.
Next, the current vaccine candidates all require two shots per person. Will people be able to get those shots at the same location? If not, who will update the databases to know who got which shot when and where? Who will be in charge of the data: will it be at the Federal level or the State level? How will coordination with local distributors be undertaken?
There are close to 330 million Americans, meaning that 700 million doses of vaccine are necessary. How quickly can they be manufactured, stored and distributed? And when we talk manufacturing, they need to not only make the vaccine itself, but the vials, needles, etc. so there are supply chain considerations.
Thus, when I look at “vaccine” I think in terms of the logistics: not just of having an appropriate candidate but being able to get it to people, and I don’t see that happening anytime soon.
Q: You said there are two shots per person. Is that it?
A: Unlikely. There’s a better chance that this will be a vaccine, like a flu vaccine, that needs to be taken annually, or at least on some schedule. While safety and efficacy testing is going on, there is no possible way to know how long protection is afforded until years have passed.
Now, we would know if protection was afforded only for a few months, and we would know that quickly. Pretend that there is a vaccine that is safe and highly effective. But six months after the second dose was given to the Phase 3 volunteers many of them suddenly came down with Covid. We would then know that it only lasted more like five months. But will it last a year? Two years? Five? We can only know that over a period of years. Certainly blood tests will be available to show whether or not individuals have neutralizing antibodies and/or T-cell protection over time, and that’s informative, but not a guarantee of long-term protection. It’s only of the problems with rushing through a vaccine.
Q: If I take a vaccine, and a better one comes out later, can I take that one too?
A: Most likely yes. Zostavax was the original shingles vaccine. It provided about 50% efficacy for those aged 50 – 70, and less after age 70. But it was all there was, so many people took it. When Shingrex came out two years ago, everyone over age 50 was advised to get it, as it had efficacy of 97%. There was no downside to the people who had already taken Zostavax.
I expect that people will take multiple Covid vaccines over time, and it shouldn’t be a problem to segue to a different version with higher efficacy.
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Please let me know if I missed a question you’d like answered.
