The Delta COVID variant is considered more contagious and could make patients sicker. Colorado health officials say vaccines still offer protection
DENVER – The Delta COVID variant originally came from India but has spread worldwide. When health officials talk about the variant emerging in Colorado, it is quick to suggest that people should be vaccinated because it will protect them.
We spoke to infectious disease specialists about how they determined the vaccine’s effectiveness against a mutating virus.
Effectiveness of the vaccine?
Dr. UCHealth’s Michelle Barron said most of the information comes from other countries.
“Most of the data we have comes from Europe. This is where they saw the Delta variant before us and had high vaccination rates,” said Barron.
Dr. Rachel Herlihy, the state epidemiologist for the Colorado Department of Public Health and Environment (CDPHE) added, “The studies done specifically with the Pfizer vaccine estimated that the vaccine was about 88% effective.”
The same is expected for the Moderna vaccine. Experts say it’s still very effective overall, but slightly lower than the 94 to 95% protection seen for other strains. Protection against the UK variant is estimated at the 90th percentile.
Barron stressed that it is very important for people to complete both doses of their vaccines. She said for the Delta variant, the vaccine effectiveness dropped to around 33% between doses, versus 60 to 80% found in studies for the original strain of COVID.
As for the Johnson & Johnson vaccine, Barron said there isn’t a lot of data yet.
“I haven’t seen a lot of data on J&J because J&J is not available in Europe. AstraZeneca, which is similar to J&J, again showed an 80% protection rate.”
Although there is still a lot to learn, Infectious Disease Doctors and CDPHE said the vaccines now available in the US are all still very effective at keeping people safe.
How did you determine the effectiveness of the vaccine?
The way health authorities have determined the effectiveness of vaccines in their own way is simple.
Through genetic sequencing, they know which variants are in circulation in a community.
“When a patient gets sick and develops symptoms and tests positive – and seeing how many of those people have received a vaccine – that is a crude way we normally get vaccine effectiveness,” said Barron.
She added that it is not a perfect or exact science, but that it does give a snapshot of how well the vaccines are working against mutations in the coronavirus.
Barron said that although the virus has changed, vaccines have been shown to be effective because “it appears that the breadth of the antibody response from vaccines is just enough to dampen the effects of the variants. We don’t know if this is for” applies to natural immunity where the antibody response appears to be quite specific to the strain you were infected with. ”
Dr. Denver Health’s Connie Price added, “In developing the vaccine it will depend on what on the virus you are using to fight the immune response. If it’s a fairly conserved part of the virus, that is, a part of the virus that doesn’t mutate very much, then it should be preserved. “
CDPHE gave further insights.
“When mutations do occur, they cause slight changes in the proteins that are present on the surface of the virus, but not all of those proteins are changed,” Herlihy said. “The virus may look a little different for our immune system. So we still have significant protection. Maybe not quite as much as we originally had for the vaccines designed for a specific type of virus that is slightly different from the virus we are. “Now see.”
How common is the Delta variant?
The Delta variant was first discovered in Colorado, Mesa County.
The local health department said in a few weeks it would become the dominant burden in their community.
Compared to the UK-based variant, Mesa County Public Health said both variants grew exponentially in a matter of weeks, but the total case numbers for the Delta variant are higher.
One case with “no known significant exposures” has so far been identified in Denver, according to city and county health officials.
“Studies from the UK looking at the effect of the Pfizer and Astra-Zeneca vaccine (not available in the US) on the Delta variant indicate a possible reduction in vaccine effectiveness with a single vaccine dose. However, when fully vaccinated, it offers protection against hospitalization and symptomatic illness. These vaccines were slightly less effective in the delta variant than in the alpha variant * (B.1.1.7), but were still effective at or over 85% in all categories with full vaccination. CDC reports that the delta Variant has potentially reduced effectiveness of monoclonal antibody treatments. This is the available intravenous outpatient treatment that prevents the onset or worsening of the disease. “
Across the state, CDPHE said the Delta variant was discovered in 20 counties, with a group of cases in Mesa County.
Why is it more contagious and harder?
All of the experts we spoke to said it seems the delta variant spreads faster and can make people sicker.
Why, Barron said, this is still under investigation.
“I’m not sure we know. We talked about how variants develop and make copy mistakes and sometimes stimulate the immune system more and sometimes have no effects at all. I suspect it was something in your immune system causing more inflammation, so I think people get sicker is this inflammatory response. Why it’s more contagious, I don’t have a good feeling. There are a couple of things I would suspect it might be able to produce more of this. If you have a full capacity virus machine, the chances are higher that you will get transmitted. I think that’s probably what’s going on with it. It is able to copy itself more. There are other factors, sometimes it binds to your nose or receptors in your mouth faster or better so you get more infections too. I don’t think we have a final answer yet. ”
What does this mean for our life?
Barron said her advice to people is the same: get vaccinated and weigh risks.
“Being fully vaccinated still gives you a lot of the freedoms and opportunities of masking, gathering, and activities that people love to do. As with all things, you need to consider yourself and your potential risks. We still know people with immunodeficiency or at Drugs that affect the immune system or diseases that affect the immune system may not start them at this high level. For people with these conditions, you should still be able to go out and do things, but maybe use a little extra caution If you are going to be in a large gathering with people you don’t know and whose vaccination status is unknown, these may be the cases where masking can be to your advantage, even if you are not immunocompromised, feel some people still do better at wearing a mask – that’s fine, you have to be in it Thinking about what I’m doing, what the potential risk of exposure is. Maybe I’m healthy, but someone in my household is vulnerable and maybe I want that extra level of pr respect. ”
CDPHE said much of the prevalence for the Delta variant is with those who are not vaccinated, so people without their syringes or partial syringes are urged to take COVID precautions seriously.
Another problem is children who are not vaccinated and too young to be vaccinated.
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