With input from Dr Monica Vasudev

1305:  China puts 22 million people under lockdown, worst coronavirus flare-up since last summer: Authorities in China have ordered testing of every resident, and have shut down transportation and cancelled weddings and other events. Over 22 million people have been asked to stay in their homes, which is twice the number affected last January in Wuhan. The flare-ups; however, continue to remain small in comparison with the devastation facing other countries, with an average of 109 new infections a day over the past week. But, they threaten to undermine the success that the country has had in controlling the virus and restarting the economy. (NY Times)

1306: Scientists in Brazil have downgraded the efficacy of the Chinese CoronaVac vaccine stating that it had an efficacy rate of just over 50%, which is way below the 78% efficacy level that was announced last week. It could have significant implications for China’s push to provide its vaccine to the developing world.

Officials at the Butantan Institute in São Paulo stated that a trial conducted in Brazil demonstrated that the CoronaVac vaccine, developed by Sinovac, had an efficacy rate just over 50%. This rate, which is slightly above the benchmark that the World Health Organization has stated would make a vaccine effective for general use, was far below the 78% level announced last week. Nearly 10 countries have ordered over 380 million doses of CoronaVac, although it is yet to be fully approved by regulatory agencies.

Unlike some other vaccines, this vaccine uses an older technology which makes use of chemicals to weaken or kill the virus, which is then put into a vaccine to incite antibodies in the recipient. However, the process of killing the virus can weaken a vaccine’s potency, and the immune response could be shorter or less effective. The lower efficacy of the vaccine would mean that it would take longer for countries that used CoronaVac vaccine to reach “herd immunity”. (NY Times)

1307: Factors and characteristics associated with headache in COVID‐19

Findings from a study published in the European Journal of Neurology show that headache was associated with a more benign COVID 19.

Investigators noted that younger age and the absence of baseline pathologies such as hypertension, atrial fibrillation and Charlson comorbidities were tied to  the presence of headache in hospitalized COVID-19 patients. This suggests that headache may present as a COVID-19 symptom in people with healthier backgrounds, thus indicating  that healthy immune systems could have a role in the development of headache.

The case-control study included 379 patients with COVID-19, hospitalized in a tertiary hospital in Madrid in March 2020. 13% of the patients developed headache, with a median age of 57.9 years and 62% were men. The remaining 331 patients who did not develop headache during their hospitalization served as controls.

The researchers found that headache was associated with younger age, lower Charlson comorbidity index, and reduced mortality, as well as with lower levels of C-reactive protein, mild acute respiratory distress syndrome, and presence of oropharyngeal symptoms.

Baseline hypertension and atrial fibrillation were more prevalent among controls. A logistic multiple regression model showed that headache had a direct association with D-dimer and creatinine  levels, use of high flow nasal cannula and arthromyalgia,  and negatively with urea levels, beta-lactamic treatment  and hypertension.

Headache was of mild or moderate intensity in 17 patients, with oppressive characteristics in 17 patients. Meanwhile, headache with holocranial localization was reported in 8 patients and temporal localization in 7 patients. The authors noted that headache was never accompanied by trigeminal autonomic symptoms among the patients.

“COVID-19-associated headache appears as an early symptom and as a novel headache with characteristics of headache attributed to systemic viral infection,” concluded the study.

Overall, the results from this case-control study suggest that the presence of headache is associated with mild inflammation and mild pulmonary alterations and with a better prognosis during COVID-19.

[SOURCE: European Journal of Neurology]

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA