Medford, Ore. -- With the Delta variant of COVID-19 still widespread in Oregon and in many areas of the US, federal officials have been talking about administering booster shots of the vaccine in order to increase antibodies that may be waning.
“We all got two shots in really close proximity. You can kind of think that as one shot . . . we did it to try to get immunity up as quickly as possible,” said Dr. Jim Shames, Jackson County's health officer. "The possibility that we may need a booster is, I think, to be expected. The timing of that, the science of that, who should get it, when should they get it — that's actually still being worked out."
Shames said that the booster shot is probably necessary for people who are immunocompromised, such as people on chemotherapy, because their bodies have difficulty producing a proper response to COVID-19. While most other people will probably need a booster eventually as well, the timing is still uncertain.
Since July of 2020, Velocity Clinical Research, which has an office in Medford, has been conducting clinical trials of the COVID-19 vaccines.
“I think one thing that has been a difference with the vaccine trials for Covid is that the number of people we've enrolled in the trials has been larger,” said Dr. Gregg Lucksinger, Medical Director at Velocity Clinical Research. "The more people you enroll in the study, the faster you get the data."
Dr. Lucksinger said that his company has conducted trials for three of the vaccines, each involving about 30,000 people, and they are still ongoing. The trial actually continues for two years, so the same subjects are still enrolled in those trials.
“What we found is that there are significantly less infections in the vaccine group compared to the placebo group, but more importantly there are less severe infections and less deaths in the vaccinated group,” Dr. Lucksinger said.
The advent of different COVID-19 variants, especially Delta, has had an impact on how vaccines are interacting with the virus. While efficacy is still quite high for staving off infection, serious illness, and death, there have been changes in how easily a vaccinated person with a "breakthrough" infection can spread the virus.
“Now what we have seen over time is the virus has mutated, and that’s a natural phenomenon — all living things as they reproduce over time, they have different characteristics and different ones are selected by the environment they live in," Dr. Lucksinger said.
Right now, the trials have reached roughly their one year mark. They have also been amended to allow for booster doses about eight months after the first dose was administered, and those subjects will be asked if they want to receive the short within the next few weeks.
"So that will extend things, we'll end up following people much longer than two years," Dr. Lucksinger said.
The reason for that, he continued, is to watch for any "safety signals" that come up in the long-term, and to see how well the vaccine stands up over time, particularly after the booster is administered. The former, Dr. Lucksinger said, would be highly unusual. Generally when vaccines have an adverse reaction, it occurs within the first few months.
If the vaccines do see a rapid loss in antibodies over a period of several months, researchers may need to work on reformulations every so often — much like the influenza vaccine, which gets an update every year or two. Dr. Lucksinger said that this remains to be seen, as some vaccines remain effective for years without needing these kinds of updates.
"I suspect that sometime in the next two months there probably will be entirely new COVID vaccine trials," Lucksinger said. He anticipates that these could include novel vaccines that target different aspects of the virus, or the same vaccines that can be administered without an injection.