Dr. David Ho is a virologist at Columbia University who gained appropriate prominence for his work with HIV. Recently, however, he has focused on the neutralization of coronavirus by monoclonal antibodies from commercial sources and in serum from individuals immunized against or infected with the SARS-CoV-2 virus.
He portrays the ability of these antibodies to inactivate the virus in tissue culture as an almost definitive marker of protection against COVID-19 in people. This ignores the fact that living people, unlike tissue culture, have cellular immunity, which is more important for survival from COVID-19.
In a paper that has been publicized over recent weeks, Dr. Ho has come to almost contrary conclusions about the ability of various antibodies to neutralize variants of the coronavirus. Interestingly, this paper was mentioned in two press releases with very different emphases.
A recent press release suggesting that two monoclonal antibodies combined as a therapy by Regeneron Pharmaceuticals were effective in neutralizing all variants of SARS-CoV-2, including the South African variant that has caused so much concern. Despite this optimism, monoclonal antibodies as a therapy for COVID-19 have been marginally effective, even when the antibodies were able to neutralize the virus in tissue culture assays like the one’s Dr. Ho uses.
Today, in the prestigious journal Nature, Dr. Ho published the paper that the prior release was based on. The paper suggested that monoclonal antibodies and serum from patients who had been infected with SARS-CoV-2 are not effective in neutralizing the South African variant of the SARS-CoV-2. Again, this work was done only in tissue culture experiments and did not examine cellular or active immunity to the virus.
Despite these limitations and the prior upbeat press release, in the conclusion of this paper Dr. Ho raises grave concerns that this will “present new challenges for monoclonal antibody therapy and threaten the protective efficacy of current vaccines.”
There are several things to remember when reading these papers. First, antibodies in tissue culture are not the same as a living human whose immune system can respond and change its immune response to meet changes in a virus. Also, nowhere in medicine is a single monoclonal antibody perceived as an effective treatment for an infection. This makes these experiments essentially irrelevant to true human disease.
There are commercial sponsors for this work and Dr. Ho is a member of the scientific advisory board of Brii Biosciences, which provided a grant to Columbia University to support this and other studies on SARS-CoV-2. It is not clear whether the change in focus of the different press releases is related to these entities.
The fact that Dr. Ho’s studies show that together just two monoclonal antibodies against the SAR-CoV-2 remain effective against all variants should give everyone hope that these variants can be defeated by our current vaccines.
The human immune system remains stronger than any tissue culture experiment can predict!