Researchers have made a breakthrough in the race to develop a safe and effective new crown vaccine,media BGR reported. An experimental vaccine from Johnson and Johnson prevents severe symptoms in hamsters exposed to the virus four weeks after being vaccinated. Johnson and Johnson researchers say this could be the first study to prove that the vaccine can prevent serious complications such as pneumonia in animal trial models. The third phase of Ad26.COV2.S human trials will begin in September, and the company hopes to include 60,000 volunteers in the study.
At least seven new crown vaccine candidates are currently in Phase 3 trials, throbbing hopes that at least one of these drugs will be effective and safe. Three of the vaccines are made in China, one in Russia and three in Europe and the United States. Yet Russia’s new crown vaccine research has drawn a lot of criticism for its lack of scientific data. Currently, the three new crown candidates tested in the United States, Europe and other countries are Moderna, Pfizer/BioNTech and AstraZeneta/Oxford. While at least one of the first experimental vaccines to enter Phase 3 is likely to be approved for COVID-19 prevention, there is no guarantee that any of the seven candidate vaccines will actually work.
Thankfully, more than 160 vaccine candidates are in different stages of testing, so even if all seven fail, hopes of successful vaccine development will not go away. Other vaccine candidates will soon enter the advanced stages of clinical trials. One of the experimental drugs will enter its third phase later this month and may recruit more volunteers than any other. What’s more, the researchers say, it may be the first drug to prove that it prevents serious illness and death after direct contact with the virus. However, there is a big warning that because the results come from preclinical trials, the subjects are not human.
The first results developed around COVID-19 immunization and vaccines came from animal trials. The researchers studied macaques to show that after exposure to SARS-CoV-2, anti-re-infection immunity ensued. Scientists at the University of Oxford have shown that their vaccine could prevent the virus from spreading to the lower respiratory tract after exposing monkeys to the same species.
Johnson and Johnson researchers chose to use Syrian golden hamsters to study the evolution of COVID-19 in vaccinated and unvaccinated animals, suggesting that the drug could prevent serious disease in vaccinated hamsters.
Scientists have found that a one-dose trial of the Ad26 vaccine candidate is enough to prevent the virus from triggering COVID-19 in hamsters. The drug causes the desired immune response, producing binding and meso-antibodies. “Our data suggest that Ad26-S.PP’s single immunity provides a strong protection against severe clinical diseases after high doses of SARS-CoV-2 infection in hamsters,” Johnson and Johnson researchers concluded in a study published in the journal Nature. “As far as we know, the vaccine’s protection against severe SARS-CoV-2 pneumonia and mortality has not been reported before.”
The researchers explained that they chose hamsters as the subject of preclinical trials because macaques do not develop severe COVID-19 after exposure to the virus. “Severe disease models will help complement current non-human primate challenge models, because protecting virus replication does not necessarily mean protecting against serious diseases,” the study reads. “In fact, in histological pathology analysis of hamsters in this study, the viral load on the lungs decreased from day 2 to day 7, while inflammatory markers continued to escalate during that time and were associated with sustained weight loss.”
The researchers explained that the data show that “progressive clinical disease in hamsters is primarily an inflammatory process that is caused by infection, but continues to increase even as virus replication decreases.” Since COVID-19 can be a serious clinical disease in humans, they believe it is important to test candidate vaccines in “preclinical models that reproduce serious clinical diseases, including outbreak pneumonia and mortality.”
Johnson and Johnson’s experimental drugs prevent the severe course of COVID-19. The post-immune hamsters lost weight compared to the control group and did not have severe pneumonia. None of the animals in question died. However, the company has not officially announced the results of its Phase 1/2 trial.
The company, which will enter Phase 3 trials later this month, hopes to include 60,000 volunteers in the study. That would make it the largest vaccine trial to date, CNBC reported. The new crown vaccine trial will need to include at least 30,000 volunteers in Phase 3 trials in the United States to show its effectiveness and safety. Johnson and Johnson uses the same technology for its new crown vaccine as the company’s experimental Ebola vaccine for the Democratic Republic of the Congo. The new Ad26.COV2.S drug combines genetic material from the new coronavirus with an improved adenovirus that causes the common cold in humans.
“As our Phase 3 pilot program begins this month, we remain committed to expanding our manufacturing and distribution capabilities to obtain our SARS-CoV-2 candidate vaccine globally if it is proven to be safe and effective in humans,” Paul Stoffels, vice chairman and chief scientific officer of Johnson and Johnson’s executive committee, said in a statement.
The U.S. government has reached a $1 billion deal with Johnson and Johnson subsidiary Jansen to buy 100 million doses of the vaccine. The agreement also allows the government to choose to order another 200 million doses of the vaccine.