COVID-19 Vaccines: A Race Against Time in the Middle of Death and Devastation!

The coronavirus disease 2019 (COVID-19) has turned into a global human tragedy and economic devastation. Governments have implemented lockdown measures, blocked international travel, and enforced other public containment measures to mitigate the virus morbidity and mortality. As of today, no drug has the power to fight the infection and bring normalcy to the utter chaos. This leaves us with only one choice namely an effective and safe vaccine that shall be manufactured as soon as possible and available to all countries and populations affected by the pandemic at an affordable price. There has been an unprecedented fast track path taken in Research & Development by the World community for developing an effective and safe vaccine. Platform technology has been exploited to develop candidate vaccines in a matter of days to weeks, and as of now, 108 such vaccines are available. Six of these vaccines have entered clinical trials. As clinical trials are "rate-limiting" and "time-consuming", many innovative methods are in practice for a fast track. These include parallel phase I-II trials and obtaining efficacy data from phase IIb trials. Human "challenge experiments" to confirm efficacy in humans is under serious consideration. The availability of the COVID-19 vaccine has become a race against time in the middle of death and devastation. There is an atmosphere of tremendous hype around the COVID-19 vaccine, and developers are using every moment to make claims, which remain unverified. However, concerns are raised about a rush to deploy a COVID-19 vaccine. Applying "Quick fix" and "short cuts" can lead to errors with disastrous consequences.

The Discovery of Hepatitis Viruses: Agents and Disease

Discovery of five hepatitis viruses A to E has followed distinctive definable phases. Human experiments at Willowbrook identified two forms of hepatitis namely infectious hepatitis and serum hepatitis. The discovery of Australia antigen in 1965 led to rapid scientific developments in viral hepatitis. SH antigen was detected in sera of patients with serum hepatitis and soon SH antigen and Australia antigen were found to be identical and selectively associated with serum hepatitis. In 1970, 42-nm Dane particles were detected in Australia antigen positive sera and linked to the virus of serum hepatitis. Subsequently, a new antigen-antibody system (e-antigen/antibody) was detected in such patients and associated with infectivity. Then, DNA polymerase was found in concentrated pellets containing Australia antigen. Hepatitis B virus (HBV) DNA cloning and sequencing of HBV followed these developments. In 1973, 27 nm hepatitis A virus (HAV)-like particles were visualized in stool samples obtained during acute phase of illness after inoculation of MS-1 strain in volunteers. Cloning and sequencing of HAV followed. In 1977, a new antigen-antibody system (δ antigen-antibody system) was identified by chance associated with HBV. Based on animal transmission studies, δ agent was found to be another virus called hepatitis D virus that is defective, requires the helper functions of HBV and interferes with HBV replication. The search for hepatitis C virus started when non-A, non-B hepatitis was recognised in multiply transfused patients with subsequent successful animal transmission. HCV was identified by a novel immunoscreening approach involving screening of cDNA libraries from infectious sera. The story of hepatitis E is historically linked to discovery of waterborne epidemic non-A, non-B hepatitis from Kashmir, India. Virus-like-particles of the agent were identified in stool samples of a human volunteer after a self-experimentation. HEV cDNA was detected in bile-enriched infectious samples and full-length HEV RNA genome was subsequently cloned and sequenced.

Meta-analysis: endoscopic variceal ligation for primary prophylaxis of oesophageal variceal bleeding

BACKGROUND

The treatment effects of primary prophylactic endoscopic variceal ligation are unclear.

AIM

To compare the treatment effects of endoscopic variceal ligation and beta-blockers for primary prophylaxis of oesophageal variceal bleeding. In addition, a subgroup analysis was done with the purpose to delineate differences in the effects of intervention that were biologically based.

METHODS

We performed a literature search for randomized controlled trials, which compared the treatment effects of endoscopic variceal ligation with beta-blockers for primary prophylaxis of oesophageal variceal bleeding. Of the 955 articles screened, eight randomized-controlled trials including 596 subjects (285 with endoscopic variceal ligation and 311 with beta-blockers) were analysed. Outcomes measures evaluated were first gastrointestinal bleed, first variceal bleed, all-cause deaths, bleed-related deaths and severe adverse events. The measure of association employed was relative risk; with heterogeneity and sensitivity analyses.

RESULTS

Variceal obliteration was obtained in 261 (91.6%) patients and target beta-blockers therapy was achieved in 294 (94.5%) patients (P = 0.19). Endoscopic variceal ligation compared with beta-blockers significantly reduced rates of first gastrointestinal bleed by 31% (RR, 0.69; 95% CI: 0.49-0.96; P = 0.03; NNTB = 15) and first variceal bleed by 43% (RR, 0.57; 95% CI: 0.38-0.85; P = 0.0067; NNTB = 11). All-cause deaths and bleed-related deaths were unaffected (RR, 1.03; 95% CI: 0.79-1.36; P = 0.81 and RR, 0.84; 95% CI: 0.44-1.61; P = 0.60 respectively). Severe adverse events were significantly less in endoscopic variceal ligation compared with beta-blockers (RR, 0.34; 95% CI: 0.17-0.69; P = 0.0024; NNTB = 28). Sensitivity analysis of five trials published in peer review journals and four trials with high quality showed results similar to those seen in the primary analysis of all the eight trials, confirming stability of conclusions. Following variceal obliteration with endoscopic variceal ligation, oesophageal varices recurred in 83 (29.1%) patients. Seven (28.1%) patients bled with one fatal outcome. In subgroup analyses, endoscopic variceal ligation had significant advantage compared wtih beta-blockers in trials including < or =30% patients with alcoholic cirrhosis, >30% patients with Child Class C cirrhosis and >50% patients with large varices.

CONCLUSIONS

In patients with cirrhosis with moderate to large varices and who have not bled, endoscopic varices ligation compared with beta-blockers significantly reduced bleeding episodes and severe adverse events, but had no effect on mortality.