Monday, November 23, 2020

70% or 90%? Which is it?

Around midnight last night I saw conflicting news alerts about the vaccine from Oxford/AstraZeneca. This is the third vaccine to publish efficacy results in the last two weeks. But 70% and 90%? It’s a huge discrepancy. Apparently it didn’t bother the stock market.

So why does it bother me? At least three reasons:

  1. Pfizer and Moderna both announced efficacy rates around 95%. Will there be a scramble to get the highest rated ones?
  2. Oxford/AstraZeneca is the first vaccine to report results that is not based on the new mRNA technology. Does this imply that the new technique is better?
  3. Oxford/AstraZeneca is the only one so far that can be stored at refrigerator temperatures, making it much easier to distribute than the other two that require sub-zero storage. Plus the vaccine is cheaper. So we would like it to be effective.

Some news sources are reporting 90% and some 70% or even both in the same article. Some even give a range, introducing a third number:

62 % to 90 % ? From BBC News

62%? Where did that come from? Why not 70%-90%? This morning information from BBC news, Nature, and the AstraZeneca press release helps to clarify some of the discrepancies. The November 23 results are based on clinical trials in Brazil and the UK. The clinical trial of 8,895 based on two full doses of the vaccine produced 62% protection. A different trial of 2,741 where volunteers received one half-dose followed a month later by a full dose gave 90% protection. According to the press release, the combined data give an average efficacy of 70%, which may be accurate statistical analysis but doesn’t represent the real-life result of any trial. Neither does the range.

The 90% with two-unequal-dose outcome will be studied further to see whether a lower first dose actually does make the immunity stronger and if so, why?

Although a few people who got the vaccine did get COVID, none were serious cases and none required hospitalization. Preliminary results from volunteers who had interim testing suggest that the vaccine may also prevent or reduce asymptomatic cases, which can also be infectious. Oxford/AstraZeneca vaccine trials are ongoing in diverse parts of the world, including the U. S., Russia, Kenya, Japan and others. Its easy storage is especially encouraging in light of the company’s no-profit pledge and commitment to world wide distribution.

Simple storage

So to answer my questions, all three vaccines reporting so far appear to be very effective and all will be in demand. There is no basis for drawing conclusions about the relative efficacy of the different methods of manufacture. Plus the newest vaccine can be stored at 36-46 degrees Fahrenheit. My own kitchen refrigerator can achieve that.

No, I don’t plan to keep it in the salad drawer, but I am glad it’s so easy to store. I plan to get a vaccine when one becomes available to ordinary people, which I expect to be soon after the pandemic anniversary date of Thursday, March 11. 108 days to go!

Postscript: The epidemiologists, bless them, badly need some public relations advice. Because I really do expect vaccines in combination with emerging great therapeutics and treatment regimens to change things. And they are all being so cautious about predicting anything. The BBC quoted Health Secretary Matt Hancock as saying we will be, “something closer to normal,” by summer. U.S. experts are equally vague. We’re facing a hard winter, guys. Dare to project a vision!

I want to know about travel, singing, hugging, and holidays. I want to give my newest granddaughter a kiss. A kiss to build a dream on.

Stay tuned.

Today’s Notable Headlines

“Covid-19: Oxford University vaccine is highly effective,” BBC News, Nov. 23, 2020. https://www.bbc.com/news/health-55040635

“Why Oxford’s positive COVID vaccine results are puzzling scientists,” Nature, Nov. 23, 2020. https://www.nature.com/articles/d41586-020-03326-w

“AZD1222 vaccine met primary efficacy endpoint in preventing COVID-19,” AstroZeneca press release, Nov. 23, 2020. https://www.astrazeneca.com/media-centre/press-releases/2020/azd1222hlr.html

“Life may be back to normal by next summer, one of world’s leading vaccine experts says,” The Telegraph, Nov. 20, 2020.

Why am I doing this?

The coronavirus pandemic will be indelibly written on our memories just as the Great Depression or the Battle of Britain left their mark on past generations. It is my intention to journal the pandemic experience from three perspectives: as a retired medical technologist, a historian (Ph.D., 2014), and an ordinary person living through an extraordinary crisis.

You are on History’s Edge.

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