Astro/noro/rota/sapo

Question 1

Mum is on rituximab and receives a dose during pregnancy. Which vaccine(s) can’t the baby have?

Answer 1

“immunisation with live vaccines should be delayed until 6 months of age in children born to mothers who received immunosuppressive biological therapy during pregnancy. In practice, this means that children born to mothers who were on immunosuppressive biological therapy during pregnancy will not be eligible to receive rotavirus vaccine (and will need to defer BCG, if indicated, for 6 months). “

From chapter 6 green book

Question 2

Which species of rota virus most commonly causes human infection?

Answer 2

Rotavirus A species based on VP6 protein. Further subclassified by G and P type using VP7 and VP4 respectively

Question 3

Rotavirus vaccine -

type?
Recipients and schedule?
Contraindications?

Answer 3

Live attenuated oral vaccine

Given as 2 doses
-First dose at 8 weeks and not later than 15 weeks
- Second dose at 12 weeks and not later than 24 weeks
Dosing schedule designed to minimise possible risk of intussusception

Contraindications
- Mother received biological immunosuppression during pregnancy. (live vaccine CI for first 6 months)
- SCID
- child with hx intussusception

Question 4

What timings can the the rota virus be given/not given?

Answer 4

First dose
- After 8 weeks and no later than 15
- Second dose 4 weeks after first and no later than 24.

Question 5

Appearance of astrovirus on EM ?

Answer 5

28-30nm (small)

5 or 6 pointer star appearance.
- Not all virions (usually around 10% and pH dependent)

Question 6

Genome of rota virus and EM appearance?

Answer 6

Looks like a wheel - rota = latin for wheel.

Genome - ds RNA gapped genome.
** the genome can rotate (antgenic shift) more than others**

Question 7

Most common strain of norovirus in uk?

Answer 7

GII.17

Question 8

Strain of norovirus associated with worse disease?

Answer 8

GII.4

Question 9

Gene which confers resistance to norovirus infection?

Answer 9

Fut2 - occurs in around 20% of European descendants. Homozygotes don’t display h proteins in their gut which is required for some noro strains to infect (esp gii.4). H protein part of ABOH blood grouping proteins.

If you’ve got 2 feet (fut) you can outrun noro

Question 10

Incubation and infectious period for noro

Answer 10

Incubation - short 12-48h
Infectious period - Symptom onset until 48h afterwards

Question 11

Vaccine trials in uk for noro?

Type of vaccine and coverage?

Answer 11

mRNA-1403 – Moderna sponsored phase 2 trial underway in the UK. Trivalent mRNA-based candidate containing mRNAs that encode for the major capsid protein 1 (VP1) of three globally prevalent Norovirus genotypes—GII.4, GI.3, and GII.3.

HilleVax - VLP vaccine with phase 2 trials underway - contains antigens to GI.1 and GII.4 genotypes