(Minghui.org) Within two days, both Johnson & Johnson and Eli Lilly paused their late-stage coronavirus vaccine clinical trials, on October 12 and 13, 2020, respectively, out of safety concerns over the highly-anticipated “cure” for the deadly virus that has infected nearly 40 million people and killed 1 million worldwide.
While it’s not clear when both companies can or will resume their clinical trials or what the specific conditions their participants are experiencing, the sudden halt to the work of the two front-runners renews the discussion about the safety of a coronavirus vaccine and the potential adverse effects it could have.
One of the major concerns regarding a coronavirus vaccine is antibody-dependent enhancement (ADE), a phenomena that could contribute to the increased severity of viral infection. Should ADE occur, the antibodies stimulated by the injection of a vaccine would enhance entry of the virus into the cells and subsequent viral replication, instead of neutralizing it. ADE could cause severe immune responses, including rapid deaths.
Unlike how antibiotics target and kill bacteria, there is no such broad-spectrum drug for viruses. Most anti-viral drugs don’t eliminate the target pathogen. Instead, they inhibit its replication by giving the human body’s own immune system more time to respond to the virus. Once the immune system wins the battle, it will develop memory of the specific antibody it produced to neutralize the virus. When the body is infected with the same virus again, such memory will activate the body’s immune system and quickly produce a large number of antibodies to tackle the pathogen.
It’s based on the same idea that vaccines, mostly non-disease-causing agents mimicking the virus, were developed to prepare the body with acquired immunity for certain pathogens.
The ADE effect, though still poorly understood, was first discovered in the dengue virus. When a person is first infected with the virus, they may have fever, headache, muscle and joint pain, and skin rash. About 1 out of 1000 would have severe symptoms such as bleeding, shock, and hemorrhagic fever. That ratio could be ten times higher, however, when a person is re-infected with the virus.
In the clinical trials for Dengvaxia, a vaccine developed by Sanofi that targets all four serotypes of the dengue virus, 295 of 20,439 children (1.44%) were hospitalized in the fifth year after receiving the third dose of the vaccine, mostly likely a result of the ADE effect.
In addition to the dengue virus, ADE has also been observed in the human immunodeficiency virus (HIV), feline infectious peritonitis virus, severe acute respiratory syndrome coronavirus (SARS-CoV), and Middle East respiratory syndrome-related coronavirus (MERS-CoV).
So far, only the smallpox virus has been eliminated through vaccination among millions of viruses that exist in nature. For more complicated viruses, the development of vaccines has been met with more difficulties and mixed results, due to the ADE effect and the virus sequences that keep mutating.
Given the fact that the novel coronavirus (Covid-19) is 80% identical to the SARS-CoV and 54% identical to the MERS-CoV, it’s very likely that ADE in the novel coronavirus will occur, leaving those who are given the vaccine with greater vulnerability to mutated virus strains.
Some scientists have proposed optimizing the design of the vaccine to minimize the potential ADE effect, such as reducing the non-neutralizing antibodies or adjusting the dosages of vaccine. However, given the coronavirus’ unstable nature and high mutation rate due to its RNA architecture (RNA is a kind of genetic molecule that is susceptible to chemical degradation in the environment), that could be a significant challenge for scientists to keep up with the head-to-head race in the development of the vaccine.
Historically, several pandemics have seen more deadly second waves, such as the 1918 Spanish Flu and the 2009 H1N1 pandemic. While the virus infection routes and the vulnerable groups it targets are highly dynamic, it’s reasonable to ask whether ADE could be one of the factors that has contributed to the deadly second waves.
On the other hand, from the perspective of traditional Chinese culture, it’s always been believed that there is a deep connection between the human mind and body, and, surface phenomena aside, plagues are often considered an indicator of the degeneration of people’s hearts and moral standards.
While scientists are racing to produce life-saving vaccines and drugs to cure the deadly Covid-19, it’s worthwhile pausing to reflect on ourselves: Is there a deeper reason for the coronavirus situation? Can we find a cure from within?