MONTREAL, August 1 – The Covid-19 pandemic is often compared with the 1918 Spanish flu, and not as often to the HIV/AIDS pandemic that emerged four decades ago despite parallels that exist between the two public health crises.
For Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), who has dealt with several infectious epidemic diseases, including HIV/AIDS and Ebola, the 40 years of progress against HIV have much to offer.
From a scientific standpoint, lessons dating back to HIV include the role of asymptomatic infection, the development of therapeutics or drugs, and vaccine design, Dr Fauci said.
Dr Fauci, who is chief medical advisor to US President Joe Biden, said when he first took care of people who were living with HIV, a virus that attacks the body’s immune system, it was clear that individuals without symptoms were spreading the infection.
“It was only when we had diagnostics to be able to identify asymptomatic people that it became clear that the patients that we were seeing were really, the tip of the iceberg.
“This is exactly what we found out a couple of months, or maybe a month into the Covid outbreak is that up to 60 per cent of the transmissions are from asymptomatic individuals, either those who were presymptomatic or those who never developed symptoms,” Dr Fauci told the 24th International AIDS Conference (AIDS 2022) here last Friday.
On therapeutics, Dr Fauci said the development of targeted drugs for HIV resulted in the design of antiviral therapeutics that inhibited vulnerable targets in the SARS-CoV-2 virus.
“The identification of vulnerable targets in the SARS-CoV-2 led to the design of drugs to inhibit vulnerable targets.
“We learned that way back in the time that we did targeted drug development with HIV, and we’ve applied that paradigm to the identification and development of drugs according to vulnerable targets of the SARS Covid 2 replication cycle – very, very similar to what we did with HIV with the integration of the integrase inhibitors, the protease inhibitors, and the reverse transcriptase inhibitors.
“We also have a similar toolkit or medicine cabinet of therapeutics (for Covid-19), particularly paxlovid, but also remdesivir, molnupiravir, and the monoclonal bebtelovimab,” he said.
Advances in HIV vaccinology, or vaccine science, also “paved the way” for Covid-19 vaccines, Dr Fauci said, although HIV vaccine development remains a scientific challenge.
“If one looks at the work that has been done literally over decades on structured-based vaccine design with HIV, to get the right confirmation of the envelope trimer to engage the B-cell repertoire, that approach of structure-based vaccine design was actually transferred in its technology to the development of the optimal immunogen for SARS-CoV-2 vaccination.
“Proper mutations stabilised the spike protein in its prefusion form, which was originally unstable but with the mutations that were induced, it put it in a stable form, which is now being used,” Dr Fauci said.
“You can see it under the category of immunogen, the S2P, is that stabilised prefusion spike protein which has been used in multiple vaccines that have been utilised extensively in the US, such as Moderna, BioNTech, J&J and most recently, some of the recombinant proteins.”
S2P or site-2 protease is a type of enzyme or protein that acts as a biological catalyst that accelerates chemical reactions.
On non-vaccine preventions, Dr Fauci cited condoms, pre-exposure prophylaxis (PrEP) – both oral and long-acting injectable antiretroviral – and treatment as prevention (TasP) as preventive approaches for HIV. For SARS-CoV-2, he listed face masks and antibodies for Covid-19 PrEP such as Evusheld.
PrEP is the use of medications to prevent the spread of disease in people who have not yet been exposed to a virus.
Dr Fauci said there are also similar frustrations in the fight against HIV/AIDS and Covid-19, such as how denialism can promote illness and death.
“To deny that HIV causes AIDS led to the unnecessary death of people who did not get access to the lifesaving medication,” Dr Fauci said. “The same holds true for people who think that Covid is a hoax and the conspiracy theorists that say that – they do nothing at all but cause unnecessary loss of life.”