However, it still stopped short of making masks compulsory, instead leaving it to each school board to make the call themselves.
The stronger wording follows on from a resurgence in Omicron cases through the start of July that now appears to have peaked at just over 10,000 daily cases.
There are currently 60,886 active cases in the country, defined as people who were identified as having the virus within the last 7 days and not yet classified as recovered.
There have been 1,546,211 cases in New Zealand since the start of the pandemic.
The 759 people with Covid in hospital are located in: Northland: 19; Waitematā: 94; Counties Manukau: 62; Auckland: 97; Waikato: 65; Bay of Plenty: 41; Lakes: 13; Hawke's Bay: 32; MidCentral: 38; Whanganui: 11; Taranaki: 18; Tairāwhiti: 2; Wairarapa: 8; Capital & Coast: 33; Hutt Valley: 29; Nelson Marlborough: 13; Canterbury:137; West Coast: 0; South Canterbury: 12; and Southern: 35.
The average age of those with Covid in hospital is 67.
The seven day rolling average of hospitalisations of people with Covid is now at 764 - up from 727 a week earlier.
Among the 22 people who died with Covid: six were from the Auckland region, one was from Waikato, three were from Bay of Plenty, one was from Lakes, one was from Hawke's Bay, one was from Taranaki, one was from MidCentral, one was from the Wellington region, two were from Nelson Marlborough, two were from Canterbury, and three were from Southern.
Two were aged in their 50s, one was in their 60s, five were in their 70s, six were in their 80s and eight were aged over 90. They included 10 women and 12 men.
The seven day rolling average of reported deaths with Covid is 25. There has also been 1976 people who've died with Covid since the pandemic began.
While daily Covid cases had now dipped below 10,000, it's not clear how much the school holidays helped slow slowed transmission - and whether cases will rise again when students are back in the classroom.
A newsletter sent to all schools Thursday night said both the Education and Health Ministries were recommending students Year 4 and up should wear masks for the next four weeks, while indoors and where it won't have a "significant impact on teaching and learning".
Associate Education Minister Jan Tinetti has also written to school boards, outlining the Government's "strong recommendation to review and enforce a mask-wearing policy as much as practicable".
Asked whether the Government had any plans to make masking compulsory, Tinetti said in a statement that winter illnesses "historically peak at the start of Term 3 which is why we have reminded schools of the Government's policy on mask wearing this week".
Meanwhile, there were 13,340 second booster vaccine doses given out yesterday and 968 first booster doses.
Thirty-one people also got their first vaccine dose yesterday.
