2 posts were split to a new topic: Moderation!
likely not much impact. If itâs a peer-reviewed journal, then the âchangesâ are likely some edits to help clarify things or to add some additional info that is believed to be helpful to a reader.
So anyway, Pfizer is reporting 90%+ early results in their Phase 3 study, which, caveats aside, is terrific news. Public health officials were expecting a vaccine with around 60% effective. Which is good enough if you have a very high vaccination rate, but indications are that it wonât be that high at all. But with 90% effective rate, you can have a vaccination rate of 60-70% and still suppress the virus.
Todayâs lecture (which will be posted in a couple days)
was about the development of the Moderna vaccine, which is extremely similar to the Pfizer vaccine, and which is expected to release preliminary results later this month. She showed all sorts of very promising data about that vaccine (which may be stable at -4C, a temp that most commercial freezers can manage) but she said that she cried when she saw the 90% preliminary effectiveness of the Pfizer vaccine. Thatâs about the best news we could have hoped for.
Also, todayâs lecture was very accessible, and I think a lot of people here would find it interesting.
So I definitely no expert. But itâs my understanding that both the Pfizer and the Moderna vaccine target the âspike proteinâ which completely new type of vaccine.
What Iâm wondering is this⌠does that mean if the virus mutates, the vaccine will remain effective as long as the virus maintains the spike protein? And, if it loses that protein, itâll be a much less dangerous virus so it doesnât matter if the vaccine doesnât work anymore? Is that the correct way to look at it?
IANAD but my understanding is the spike protein is what allows the coronavirus to infect human cells. So if it didnât exist then it wouldnât infect us
Unfortunately, mutations to the spike protein wonât necessarily make the virus less dangerous. They could make the vaccine less effective, though. Thatâs why Denmark was considering killing every mink in the country (they seem to have pulled back on that though).
Basically a variant of COVID-19 has emerged among minks in Denmark that has (among other changes) altered the spike protein; as a result it appears that antibodies for main-strain COVID-19 are less effective. (Minks are susceptible to COVID-19, and apparently unlike most animals can transmit that infection back to humans.)
Huh. I feel like every time there is a little bit of good news with this virus, a Danish mink takes a big shit all over it.
I think itâs more like the flu vaccine . . . but once we have something in place for the current strain, ongoing research for what the ânextâ vaccine will need to be and then mass produce it.
I agree. The original estimates for the first round vaccine was around 60% effective. Thatâs flu vaccine territory. But, 90%? We could crush this virus if that plays out.
I doubt that weâll see the 90% once it hits the general population. I agree that itâs promising, but Iâm guessing that the number will be closer to 70% since the current test population is unlikely to account for ALL possible people that will have different responses to the vaccine.
No, the flu mutates much faster than most viruses, and preliminary information suggests the covid-19 mutates fairly slowly. We need a new flu vaccine every year because the flu changes every year, not because our immunity to it wanes. (and the woman who spoke at that MIT course on Tuesday is also working on a universal flu vaccine, which maybe we are close to getting.) In contrast, our immunity to coronaviruses wanes over time. We need a different flu vaccine every year, but if we need boosters for covid, it could be the exact same vaccine.
fwiw, our immunity to tetanus and pertussis also wanes with time, and getting the same immunization we got 10 years previously does the trick to boost our immunity.
Yes, the mink thing shows that it CAN mutate enough to matter. And that will remain a risk. The WHO article says the mutation makes the virus slightly less susceptible to neutralizing antibodies, which is bad, but probably not terrible.
They arenât testing the vaccines on babies or the frail elderly, but Iâve looked at some of the calls for volunteers, and they are looking for people up to age 85, and for a wide racial diversity in the phase III trials.
And this is why I donât think that weâll see the 90% rate when it rolls out to the general public; potential sample bias.
note that they didnât report â90%â. They reported âbetter than 90%â. Yes, immune compromised people arenât accepted in vaccine studies, and population numbers include the immune compromised. But
- I donât think thereâs a ton of bias such that people who volunteer for vaccine trials are more likely to develop immunity that others. (People intentionally excluded ARE less likely to develop immunity, but they donât represent a huge fraction of the population.)
- The preliminary numbers are preliminary, of course, and thereâs no doubt a wide 90% confidence interval. That being said, given whatâs been published, it looks like a 90% effective vaccine may very well be possible. Thatâs very good for a vaccine, but there are other vaccines that are that good.
Yeah, and itâs also worth pointing out that the Guardian article I linked above says the problematic mink variant hasnât been seen in the wild for over a month. I suspect the radical action suggested in Denmark stemmed more from concerns about getting blamed for a âDanish fluâ. Folks can talk a big game about China & COVID, but Chinaâs a big enough player economically thereâs not much they can do â but if you wanted to look tough, Denmark would be a very soft target.
Last I looked a lot of vaccines â mumps, measles, chickenpox, polio, tetanus â are around 90% effective (and sometimes even better). The flu vaccine is a bit of an outlier, but that just stems from the fact that there are a lot of flu variants and the developers have to guess 6 months in advance which ones to protect for. So I wouldnât be surprised if the 90% effectiveness for the COVID vaccine sticks.
But those 90% effective vaccines were also developed over a period of several years. (See measles example below.)
Iâm not arguing that the current proposed vaccine wonât eventually be as effective; just skeptical that itâs going to be just as effective as the phase III trials are showing when itâs first rolled out to the general population. Part of this is based on just how wide the variation of symptoms shown for people who do end up testing positive for COVID-19.
Thereâs been a lot of work on vaccines since the measles vaccine was developed. And this vaccine was based on work that had previously been done to develop vaccines for SARS1 and MERS. The lab that produced the Moderna vaccine manufactured the first batch just 3 DAYS after the sequence of the SARS2-COVID spike protein was published, in January. They could do that because they leveraged what they had learned about coronavirus vaccines based on years of research with SARS1 and MERS.
Fwiw, in the preliminary, phase 1 trials, 100% of (a very small number of) participants developed robust immunity after the second dose of vaccine.
News out of Russia that their vaccine candidate is showing 92% effective. I mean, how much can you trust data from Russia, I dunno, but wouldnât it be great if there were multiple vaccines that go to market that were that effective. Maybe, just maybe, this virus will be easy to control with effective vaccines.