November 10th, 2020

Promising COVID-19 Vaccine Results and Progress on HIV Prevention — All in One Great Day

Kaspar Hauser (1828–1833)

Monday, November 9, in the bedeviled year 2020, was an astounding day for research on prevention of infectious diseases — really unprecedented.

First — we awoke to hear that the Pfizer-BioNTech experimental COVID-19 vaccine was “90% effective” in preventing the disease after the second (of two) doses.

This was a planned interim analysis, taking place after 94 cases had occurred in 44,000 volunteers, with 39,000 completing the full series. No major safety concerns yet reported.

We of course need to review the full data, but these results are far better than any of us expected. For other viral respiratory infections, we have flu vaccine at one extreme of efficacy (20-50%, depending on the season), and measles at the other (90% or higher, and lifelong). Who could have predicted that the first SARS-CoV-2 vaccine result would be closer to the latter?

My ID colleague Dr. Mark Siedner and I wrote a primer on how to interpret the data, when they come out. Check it out!

Second — we learned the results of a critical HIV prevention study, HPTN 084, which compared TDF/FTC given once daily to injectable cabotegravir given every 8 weeks in HIV-negative women in Africa. Over 3000 women were enrolled at sites located in Botswana, Eswatini, Kenya, Malawi, South Africa, Uganda, and Zimbabwe.

Thirty-four HIV infections occurred in the TDF/FTC arm vs only four in the cabotegravir arm, a nearly 9-fold difference. As with HPTN 083 done in men who have sex with men and transgender women, the TDF/FTC strategy was effective, but the cabotegravir strategy significantly more so — a difference big enough in 084 to prompt the safety monitoring board overseeing the study to recommend stopping the blinded phase of the trial.

In a background of disappointing PrEP studies conducted in this population (African women), these results are particularly impressive. And because the Pfizer vaccine study dominated the day’s news (understandably), you might have missed this — hence I’m highlighting it here.

Wow, what a day. Thanksgiving came early in 2020, didn’t it?

4 Responses to “Promising COVID-19 Vaccine Results and Progress on HIV Prevention — All in One Great Day”

  1. Sri Edupuganti says:

    Truly a momentous day for Infectious Diseases! To add to the good news, the Lilly COVID-19 monoclonal antibody has EUA for outpatient treatment of COVID-19.

  2. John SM Leung says:

    Is it true that the Pfizer COVID-19 vaccine requires storage at minus 70 degree C. If so, would that pose some logistic problem in world-wide distribution especially to underprivileged areas? Or maybe the price of the vaccine would have excluded those areas anyway.

  3. adam lake says:

    The other theme of the day is refigeration – both CAB needing refrigeration (anticipating the volume we’ll need for this is going to require purchasing another fridge) and Pfizer’s vaccine are basically needing dry ice to keep stable.

  4. Becca Widener says:

    Great news about the cabotegravir prevention study! I would love, love, love to see a long term injectable used for nPEP- it would make it so much easier for victims of sexual assault to get a shot when they present to the ER and not have to take a pill each day, a daily reminder of their trauma.

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HIV Information: Author Paul Sax, M.D.

Paul E. Sax, MD

Contributing Editor

NEJM Journal Watch
Infectious Diseases

Biography | Disclosures | Summaries

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