{"id":291465,"date":"2021-07-06T00:12:40","date_gmt":"2021-07-05T21:12:40","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/vaccines-extremely-effective-against-covid-variants-of-concern-canadian-study\/"},"modified":"2021-07-06T00:12:40","modified_gmt":"2021-07-05T21:12:40","slug":"vaccines-extremely-effective-against-covid-variants-of-concern-canadian-study","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/vaccines-extremely-effective-against-covid-variants-of-concern-canadian-study\/","title":{"rendered":"#Vaccines extremely effective against COVID variants of concern: Canadian study"},"content":{"rendered":"

“#Vaccines extremely effective against COVID variants of concern: Canadian study<\/strong>”<\/p>\n

\n Whether it’s Pfizer, Moderna or Astra Zeneca, the vaccines used in Canada ‘are doing exactly what they should be doing,’ including against the Delta variant\n <\/div>\n
\n Researchers around the world are sifting through data to determine how the leading COVID-19 vaccines are doing against the variants of concern. Now, a big pre-print study <\/a>from Ontario suggests that the vaccines used in Canada\u2014Pfizer, Moderna and AstraZeneca\u2014are very effective against the four big variants of concern: Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2).<\/p>\n

\u201cOur findings suggest that even a single dose of these three vaccine products provides good to excellent protection against symptomatic infection and severe outcomes caused by the four currently circulating variants of concern, and that two doses are likely to provide even higher protection,\u201d the authors concluded. The study\u2019s results showed that being fully vaccinated gives a person roughly the same protection against Delta as Alpha, Beta and Gamma. The data shows that the vaccines are doing even better than previous studies suggested against the variants in terms of symptomatic infection as well as hospitalization and death.<\/p>\n

\u201cVaccines are doing exactly what they should be doing,\u201d says Dr. Zain Chagla, an infectious diseases physician at St. Joseph\u2019s Healthcare in Hamilton and an associate professor at McMaster University. \u201cGetting vaccinated is the most effective intervention against the spread of COVID-19 and all of the variants.\u201d<\/p>\n

RELATED:\u00a0What is the risk of getting myocarditis after an mRNA COVID vaccine?<\/strong><\/p>\n<\/blockquote>\n

The study compared the vaccination status of community-dwelling Ontarians who were exhibiting COVID symptoms and got tested between December 2020 and May 2021, dividing those 420,000 people into two groups: those who tested positive for COVID-19 and those who tested negative. The researchers used information from the province\u2019s rapidly expanding genomic sequencing program to track the variants of concern (VOC) among those who were positive. They also point out that the number of cases of specific VOCs in the study depends on when those variants were first identified in the province.<\/p>\n

The team was led by researchers at ICES<\/a>, an Ontario-based research body that evaluates health care delivery and outcomes, as well as the Dalla Lana School of Public Health at the University of Toronto and Public Health Ontario. The preprint study was uploaded to medRXiv<\/a>, a free online archive and distribution server for complete but as yet unpublished studies.<\/p>\n

The study\u2019s topline results looked at vaccinated people who had received the first dose at least 14 days earlier or the second dose at least seven days earlier. (Because Ontario only recently switched to promoting second doses in the community, there wasn\u2019t always enough data to compare the effectiveness of vaccines versus the newest variant, Delta; as well, the eight- to 12-week interval between doses of AstraZeneca reduced the amount of its data.)<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
PFIZER<\/b><\/td>\nMODERNA<\/b><\/td>\nASTRAZENECA<\/b><\/td>\n<\/tr>\n
Symptomatic infection<\/b><\/td>\n<\/tr>\n
vs. Alpha:
\n1st dose: 66% effective<\/p>\n

2nd dose: 89%<\/p>\n<\/td>\n

vs. Alpha<\/p>\n

1st dose: 83% effective<\/p>\n

2nd dose: 92%<\/p>\n<\/td>\n

vs. Alpha<\/p>\n

1st dose: 64% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 60% effective<\/p>\n

2nd dose: 84%<\/p>\n<\/td>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 77%<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 48%<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n

vs. Delta:<\/p>\n

1st dose: 56% effective<\/p>\n

2nd dose: 87%<\/p>\n<\/td>\n

vs. Delta:<\/p>\n

1st dose: 72%<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n

vs. Delta:<\/p>\n

1st dose: 67%<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n

Hospitalization or death<\/b><\/td>\n<\/tr>\n
vs. Alpha:<\/p>\n

1st dose: 80% effective<\/p>\n

2nd dose: 95%<\/p>\n<\/td>\n

vs. Alpha:<\/p>\n

1st dose: 79% effective<\/p>\n

2nd dose: 94%<\/p>\n<\/td>\n

vs. Alpha:<\/p>\n

1st dose: 85% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 77% effective<\/p>\n

2nd dose: 95%<\/p>\n<\/td>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 89% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n

vs. Beta\/Gamma:<\/p>\n

1st dose: 83% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n

vs. Delta:<\/p>\n

1st dose: 78% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n

vs. Delta:<\/p>\n

1st dose: 96% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n

vs. Delta:<\/p>\n

1st dose: 88% effective<\/p>\n

2nd dose: n\/a<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The results \u201clook very similar if not a bit better than the United Kingdom,\u201d Chagla notes. In particular, Moderna seems to be more effective after first doses than either Pfizer or AstraZeneca, the authors note. As well, the effectiveness of AstraZeneca in the Ontario study app<\/a>ears to be higher than one released in June from Public Health England. Chagla wonders if the discrepancy is because of Canada\u2019s first-dose first regimen that delayed second doses by up to 16 weeks, thus \u201callowing more immune maturation before second doses.\u201d<\/p>\n

On July 5, Ontario reported<\/a> 170 new cases of COVID-19 and just one admission <\/a>to an ICU and one death. \u201cOur first-dose policy is likely what is giving us the sustainable decreases we see today, and the lack of acute care [demand] as compared to prior\u201d months, Chagla says. \u201cIn the face of a more infectious and potentially more virulent variant, we are seeing hospitals and ICUs empty and the health care system restart.\u201d<\/p>\n

As Canada rolls out the country\u2019s most complex vaccination project to date, <\/i>Maclean\u2019s presents <\/i>Vaxx Populi, an ongoing series<\/a> in which Patricia Treble tackles the most pressing questions related to the new COVID-19 vaccines. Send us a question you\u2019d like answered at vaccines@macleans.ca. If you have specific questions about your own health, we recommend consulting a family doctor or the local public health authority in your area.<\/i>
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