A teacher and at least one pupil have been struck down with covid in a third outbreak to hit the same school.
Parents were told of the latest cases at Houston Primary in a letter on Monday night.
The last time the school was hit it lead to an entire class being put into self isolation.
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But new regulations mean only close contacts of those who have tested positive will be absent from school.
Health bosses are refusing to say how many pupils and staff are linked to the latest outbreak, claiming revealing the number would break “patient confidentiality”.
Renfrewshire Council also failed to admit how many people have tested positive and how many close contacts have been told to remain at home.
A spokesman for NHS Greater Glasgow and Clyde said: “We are aware of covid cases linked to Houston Primary School.
“To respect and maintain patient confidentiality, no further details will be released, however, we can confirm any identified positive cases and contacts have where appropriate been advised to self-isolate.
“We would like to remind everyone to adhere to the guidance set out on NHS Inform and Scottish Government websites, especially the latest advice around self-isolation and seeking a test if you display any covid symptoms.
“We would also encourage members of the public to please make use of the asymptomatic testing sites across the area.”
Houston Primary has a roll of 486 pupils and in June an entire class and their teacher were put into self isolation because of Covid-19 cases.
Twenty nine children in P4B were sent home after being contacted by health officials.
This followed an identical situation in May involving another of the three Primary 4 classes at Houston.
A spokeswoman for Renfrewshire Council said: "Our schools continue to follow all national guidance on coronavirus protection measures.”
