Animal research

Update on AIDS and Zika Vaccines – Speaking of Research

April 19, 2021
Professor Christopher Petkov

While we have focused on updates on Covid-19 vaccines and their reliance on research with non-human animals, including primates (as an example, see here), two more Developments focused on treatments for AIDS and Zika fever have caught our attention.

These fall under the theme #MPAR, made possible by animal research.

Male rhesus macaque. Source: Kathy West.

Permanently stop the HIV virus

the Acquired immunodeficiency syndrome (AIDS) is caused by the The human immunodeficiency virus (HIV) and its variants. If a person is infected with this blood-borne virus, the virus causes severe impairment of the immune system which could be fatal. AIDS makes a person vulnerable to diseases which, moreover, are well controlled by the immune system.

Current treatments for AIDS include antiviral drugs that must be taken throughout a person’s life to control the virus. Taking antivirals for such a long time can have side effects. However, antivirals can be very effective in keeping the virus at bay, reducing both the likelihood of the disease occurring and the virus being passed on to others.

Other treatments involve vaccines that help protect the person against HIV or are therapeutic in people with HIV to reduce their dependence on antiviral drugs. The problem is that HIV viruses, like all viruses, change or mutate regularly. These changes by the virus can sometimes give it the ability to evade an otherwise effective vaccine against other variants. Thus, scientists must remain vigilant and regularly obtain scientific information on how vaccines could be updated to help the body fight viruses.

There is also a need to better understand how to stimulate the body’s responses to fight the virus, thereby making vaccines more effective. For example, there is still hope that a highly effective HIV vaccine that helps immune cells, such as T lymphocytes to destroy cells in the body infected with the virus, could potentially eliminate the virus entirely from an infected person.

This ongoing process of vaccine development and refinement relies on #animal research and, as such, can be labeled #MPAR.

Animal research can also provide information about the safety and likely side effects of potential vaccines, as well as information that cannot be obtained in humans about the impact of the disease on the cells of the body or on the human body. how vaccines work.

Animal research, however, needs to be closely related to human variants of the disease (HIV), which can be done through tests comparing the effects on both non-human animals and humans. For example, monkeys are affected by the monkey variants of the virus known as Simian immunodeficiency virus (IF V). However, the variants of the virus are not identical, which necessitates the additional step of performing the direct comparison with the variants of human HIV. Rather than assuming that because the vaccine is effective in monkeys it will also work in humans, this hypothesis needs to be scientifically tested. There are also several types of human variants of HIV, which may require different vaccines for each human variant.

This permanent scientific effort emphasizes the need for efficient animal models and research may continue even years after the first series of vaccines have been developed. It also highlights the need for scientists to explore different vaccine options, including better understanding how vaccines work and how safe they are, whereby research with relatively few animals can have a significant positive impact on human medicine and health.

About 100,000 cells of rhesus macaques, grouped by similarity. Red blood cells come from monkeys infected with the simian-human immunodeficiency virus, while blue blood cells come from uninfected monkeys.

Breakthrough in HIV vaccination efforts

Researchers from Oregon Health Sciences University recently published several scientific papers to report on potential improved treatment for SIV and link to human HIV. Their approach is based on a cytomegalovirus (a modified beneficial version of a herpes virus). By understanding how the vaccine works and how it can be modified to be more effective against SIV in monkeys, scientists have obtained evidence to suggest that it is likely to be highly effective against HIV, also establishing the scientific bridge with humans along the way by modifying the vaccine. the means necessary to be effective against HIV.

This exciting news is a direct result of research on non-human primates for a disease that, since its inception, has claimed more than 34 million lives.

This promising improved vaccine can now enter clinical trials to be evaluated for its effectiveness. Even if the vaccine being tested does not work as well as expected in clinical trials, the established animal research foundation will help accelerate future modifications and improvements to the vaccine.

Thus, #animalresearch will continue to be an important part of the scientific foundation that both supports current potential treatment and leads to future ones, even if not all scientific studies with research animals lead directly to a clinical trial in the man.

Zika virus vaccine goes to preclinical testing

the Zika The virus is spread by mosquitoes and causes mild or no symptoms, but it can cause serious birth defects in the baby of an infected pregnant woman. This is not to say that there is little impact on the infected person, as some people infected with the Zika virus may suffer from disorders like Guillain Barre syndrome, where the immune system attacks the peripheral nervous system affecting a person’s ability to move and feel. Currently, a number of potential Zika virus vaccines are in clinical trials.

Image of a baby with microcephaly (left) compared to a normal baby (right). This is one of the potential effects of the Zika virus. Signs of microcephaly may appear a few months after birth.

The University of Connecticut recently reported on a Zika vaccine in preclinical studies. Scientists used the genetic sequence of the virus to create virus-like particles. Introducing these particles into the body as a vaccine can stimulate the immune response against the virus and thus protect the individual against Zika infection.

The use of viral-like particles makes the vaccine safer as the particles themselves are biologically designed not to cause infection. This strategy is similar to some of the Covid-19 vaccines which have been developed to introduce a prickly protein from the Covid-19 virus to induce the immune system to fight viral infection, but which in itself will not harm the body. .

the Scientists at the University of Connecticut tested the effectiveness of the Zika vaccine in mice. The results of their preclinical studies with mice were promising and now have the potential to lead to clinical trials in humans to assess their efficacy in humans.

At a time when, due to the Covid-19 pandemic, we are finally starting to see the number of lives lost to the disease drop dramatically thanks to prevention and vaccination efforts, these new developments give us confidence in scientists who work for global benefit.

The scientific benefits of animal research will be a relief not only for Covid-19 containment efforts, but also for the many other diseases that affect millions of people, such as those caused by the HIV and Zika viruses.