New Australian heat tolerant COVID-19 vaccine heads to human trials

As the global pandemic continues to rage and cause havoc one of the biggest problems vaccine makers have is getting their vaccines into people’s arms without them spoiling in the heat first. So it shouldn’t come as a surprise that scientists have been trying to find new solutions to ironically what’s an old problem.

Now, a new heat tolerant COVID-19 vaccine has delivered strong preclinical results. The vaccine can remain stable for up to 30 days at around 37 °C (98 °F) and researchers are looking to begin human trials later this year.

One particular challenge in effectively distributing COVID-19 vaccines across the world is the need for most vaccines to be kept at cold temperatures. Pfizer and BioNTech’s mRNA vaccine, for example, famously requires ultra-cold storage between -80 °C and -60 °C (-112 °F to ‑76 °F) making delivery to remote communities profoundly difficult and expensive, if not impossible.

Recent research from Pfizer amended those temperature guidelines, finding normal freezer temperatures of between -25 °C to -15 °C (-13 °F to 5 °F) are safe for at least two weeks. But even then, cold storage supply lines still make it challenging to widely distribute the vaccine.

“A thermostable or ‘warm vaccine’ is critical for remote or resource-limited locations with extremely hot climates which lack reliable cold storage supply chains, including regional communities in Africa, Australia’s outback, and the Indo-Pacific region,” says Rob Grenfell, from Australia’s national science agency, the CSIRO.

The new vaccine was developed by biotech startup Mynvax, in conjunction with the Indian Institute of Science. Reporting in the journal ACS Infectious Diseases, researchers found the vaccine produces robust neutralizing antibodies against SARS-CoV-2 in mouse and guinea pig models.

“Our data shows that all formulations of Mynvax tested result in antibodies capable of consistent and effective neutralization of the Alpha, Beta, Gamma and Delta SARS-CoV-2 variants of concern,” says S Vasan, co-author on the new study.

This heat-tolerant vaccine formulation was found to be impressively stable in warm temperatures. It is effective for a month at 37 °C (98 °F) temperatures and even remained stable for up to 90 minutes at boiling temperatures of 100 °C (212 °F).

These promising preclinical results pave the way for a human trial to kick off later this year. Researchers hope a heat-tolerant COVID-19 vaccine with efficacy against newer SARS-CoV-2 variants will help deliver vaccines to remote communities.

The new study was published in the journal ACS Infectious Diseases.

Source: CSIRO