Experts on why HIV jabs took long to develop, test

Dar es Salaam. The complex nature of the Human Immunodeficiency Virus (HIV) has been named as one of reasons that scientists have struggled to develop its vaccine since the pandemic burst onto the scene nearly four decades ago.

This comes on the heels of efforts for Covid-19 vaccines development globally leaving many questioning why scientists have taken longer to find one for HIV/Aids.

The Citizen has learnt that one of the reasons lies in the complex nature of the HIV virus. In particular, this includes the remarkable HIV strain diversity and the immune evasion strategies of the virus.

According to National Institute for Medical Research (NIMR) head for HIV and Reproductive Health Research, Dr Lucas Maganga, the HIV virus is not just one virus but there is a complex diversity and genetic variations among many strains.

“The virus replicates so fast and in the process it makes so much errors resulting into many viral mutations, the mutant viruses can recombine with other strains during infection making many more recombinant virus. Hence, developing a vaccine that is able to target all viral strains and recombinant viruses remains a huge challenge,” he said.

Dr Maganga said vaccine development was a very costly and complicated procedure that needed huge investments, however, the health community was optimistic with the current bio-technology developments.

Muhimbili Natinal Hospital’s Internal Medicine physician Elisha Osati told The Citizen that the HIV virus make up was complex, being part of the class of viruses known as retroviruses that use RNA to encode their genetic information.

“The virus still has plenty of tricks that let it linger in the body after entering, this includes the ability to quickly mutate parts of its structure, thus scientists have so far become fruitless in finding vaccines,” Dr Osati said.

However, scientists are optimistic that the advances in scientific understanding and technology as well as the significant efforts by the global health community would provide better results.

New developments in technology and bio-tech, to be specific, have helped and hence the new development including the soon to be human trials by the American based pharmaceutical Moderna, he said.

The company discussed plans to test two potential candidates, named mRNA-1644 and mRNA-1574, involving 56 healthy volunteers who test negative for HIV.

The medic also noted that there were logical errors in comparing the HIV and Covid-19 vaccine efforts.

“There are two different diseases, though both are global pandemic but coronavirus spreads and kills faster than HIV,” said Dr Osati.

According to the United Nations Programme on HIV/Aids (UNAIDS), 37.7 million people have been infected globally, with the vast majority of people with HIV are in low- and middle-income countries.

“Sub-Saharan Africa is home to two thirds (67 percent) of people living with HIV,” UNAIDS stated in its 2021 global Aids update.

With nearly 26 million infected in the region, the sub Saharan is seconded by Eastern and southern Africa, 4.7 million (13 percent) in western and central Africa, 5.7 million (15 percent) in Asia and the Pacific, and 2.2 million (6 percent) in Western and Central Europe and North America.

In Tanzania, the country has nearly 1.7 million living with the disease; however it has succeeded in reducing the number of new infections by a half, according to the Tanzania Commission for Aids (Tacaids).

Tacaids indicated that HIV infections have been reduced from 130,000 annually in 2001 to 68,400 in 2019.

Recently, the Minister of State in the Prime Minister’s Office (Policy, Parliamentary Affairs, Labour, Youth, Employment and Persons with Disability), Ms Jenista Mhagama stated that the country had slashed by a half the number of deaths associated with Aids.

She said that the number of deaths has dropped from 64,000 in 2010 to 32,000 in 2020.