In this news, we discuss the Next crop of COVID-19 vaccine developers take more traditional route.
CHICAGO / BERLIN (Reuters) – The handful of drugmakers who are dominating the global coronavirus vaccine race are pushing the boundaries of vaccine technology. The next crop in development features more conventional proven designs.
The world will need several different vaccines to tackle the COVID-19 pandemic, given the scale of global needs, varying effects on different populations, and possible limits of effectiveness in the first harvest.
Many of the leading candidates currently in the final stages of testing are based on new, largely unproven technology platforms designed to produce vaccines at high speed. They include the messenger RNA (mRNA) technology used by Moderna Inc and Pfizer Inc with its partner BioNTech SE, and the inactivated cold virus platforms used by the University of Oxford / AstraZeneca Plc, Johnson & Johnson and CanSino Biologics, whose vaccine has been approved for military use in China.
Merck & Co began testing a COVID-19 vaccine in September based on a weakened measles virus that delivers genes for the novel coronavirus into the body to stimulate an immune response to the coronavirus.
Of these, only the technology proposed by J&J and CanSino that uses cold viruses as vectors to deliver coronavirus genetic material has ever produced a licensed vaccine – for Ebola.
The next group of applicants – with advanced trial results expected in the first half of 2021 – are heavily biased towards approaches that have produced effective vaccines.
Conventional methods include using a killed or inactivated version of the pathogen that causes disease to elicit an immune response, such as those used to make vaccines against influenza, polio and rabies.
Protein-based vaccines that use purified fragments of the virus to stimulate an immune response are also more common. Vaccines against whooping cough or whooping cough and shingles use this approach.
French drug maker Sanofi is developing a protein-based COVID-19 vaccine using the same approach used for its seasonal flu vaccine Flublok. Sanofi plans to begin the final phase of testing in early December, with approval slated for the first half of 2021.
Although Novavax Inc has yet to produce a licensed vaccine, it uses similar purified protein technology and plans to start an advanced stage US trial involving 30,000 volunteers by the end of November.
“These are more traditional approaches, so we can feel more comfortable having a lot of experience with them,” said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia.
Offit also sees promise in some of the inactivated virus vaccines developed by Chinese researchers, including Sinopharm’s China National Biotec Group (CNBG), one of the few first-crop developers using a traditional technique.
Other second-wave developers are making virus-like particle (VLP) vaccines, which mimic the structure of the coronavirus but contain no genetic material.
VLP vaccines can be produced in a variety of different cell types, including cells of mammals, bacteria, insects, yeasts, and plants. This approach has been used to develop vaccines against hepatitis B and human papillomavirus.
Medicago, of Quebec, is testing a VLP COVID-19 vaccine grown in tobacco plants with support from tobacco company Philip Morris.
Medicago has yet to produce an approved vaccine, but has completed large-scale testing for a seasonal flu vaccine using this approach. It plans to begin mid-term trials of its COVID-19 vaccine next month and aims to manufacture up to 1 billion doses per year by 2023.
Others watch alternative administration methods, such as the nasal spray vaccine developed by a team from Xiamen University, University of Hong Kong and Beijing Wantai Biological Pharmacy Enterprise, which is based on an influenza virus amended.
The second crop, however, could face problems completing large studies if current leaders bring their vaccines past the finish line in the coming months.
“If we get a super vaccine in December, from company x, which is on the market, it will be difficult to recruit participants for further studies,” said Peter Kremsner of the University Hospital in Tuebingen, Germany.
“So everyone will say, if the vaccine exists, I’m going to get vaccinated now with this vaccine. This will definitely be a problem for recruitment, ”added Kremsner, who is testing CureVac’s COVID-19 mRNA vaccine in early clinical trials with support from the Bill & Melinda Gates Foundation.
On the other hand, it is easier and faster to prove its effectiveness when community spread of the virus is endemic, as is happening again in the United States, Europe and elsewhere, a potential benefit for companies launching large-scale vaccine trials in the near future.
Reporting by Rocky Swift in Tokyo and Julie Steenhuysen in Chicago; Additional reporting by Kate Kelland in London, Ludwig Burger, Caroline Copley in Berlin, Sangmi Cha in Seoul and Allison Martell in Toronto; Written by Sayantani Ghosh; Editing by Miyoung Kim, Peter Henderson and Bill Berkrot
Original © Thomson Reuters